diff --git a/cmake/Modules/Packages/VTK.cmake b/cmake/Modules/Packages/VTK.cmake
index a0de1e0ff46..48b1cdba112 100644
--- a/cmake/Modules/Packages/VTK.cmake
+++ b/cmake/Modules/Packages/VTK.cmake
@@ -1,3 +1,5 @@
+# FindVTK requires that C support is enabled when looking for MPI support
+enable_language(C)
 find_package(VTK REQUIRED NO_MODULE)
 target_compile_definitions(lammps PRIVATE -DLAMMPS_VTK)
 if (VTK_MAJOR_VERSION VERSION_LESS 9.0)
diff --git a/doc/src/Build_extras.rst b/doc/src/Build_extras.rst
index 8465bea8290..a278b393c54 100644
--- a/doc/src/Build_extras.rst
+++ b/doc/src/Build_extras.rst
@@ -232,7 +232,7 @@ option in preparations to run on Aurora system at Argonne.
 
 .. code:: bash
 
-   # CUDA target (not recommended, use GPU_ARCH=cuda)
+   # CUDA target (not recommended, use GPU_API=cuda)
    # !!! DO NOT set CMAKE_CXX_COMPILER !!!
    export HIP_PLATFORM=nvcc
    export HIP_PATH=/path/to/HIP/install
diff --git a/src/BOCS/fix_bocs.cpp b/src/BOCS/fix_bocs.cpp
index 25471d04a48..0c4d6a41ad8 100644
--- a/src/BOCS/fix_bocs.cpp
+++ b/src/BOCS/fix_bocs.cpp
@@ -466,37 +466,33 @@ void FixBocs::init()
 
   // set temperature and pressure ptrs
   temperature = modify->get_compute_by_id(id_temp);
-  if (!temperature)
-    error->all(FLERR,"Temperature compute ID {} for fix bocs does not exist", id_temp);
-
-  if (temperature->tempbias) which = BIAS;
-  else which = NOBIAS;
+  if (!temperature) {
+    error->all(FLERR,"Temperature compute ID {} for fix {} does not exist", id_temp, style);
+  } else {
+    if (temperature->tempflag == 0)
+      error->all(FLERR, "Compute ID {} for fix {} does not compute a temperature", id_temp, style);
+    if (temperature->tempbias) which = BIAS;
+    else which = NOBIAS;
+  }
 
   if (pstat_flag) {
     pressure = modify->get_compute_by_id(id_press);
     if (!pressure)
-      error->all(FLERR,"Pressure compute ID {} for fix bocs does not exist", id_press);
+      error->all(FLERR,"Pressure compute ID {} for fix {} does not exist", id_press, style);
+    if (pressure->pressflag == 0)
+      error->all(FLERR,"Compute ID {} for fix {} does not compute pressure", id_press, style);
   }
 
-
-  if (pstat_flag)
-  {
-    if (p_match_flag) // MRD NJD
-    {
+  if (pstat_flag) {
+    if (p_match_flag) { // MRD NJD
       auto pressure_bocs = dynamic_cast<ComputePressureBocs *>(pressure);
-      if (pressure_bocs)
-      {
-        if (p_basis_type == BASIS_ANALYTIC)
-        {
+      if (pressure_bocs) {
+        if (p_basis_type == BASIS_ANALYTIC) {
           pressure_bocs->send_cg_info(p_basis_type, N_p_match, p_match_coeffs, N_mol, vavg);
-        }
-        else if (p_basis_type == BASIS_LINEAR_SPLINE || p_basis_type == BASIS_CUBIC_SPLINE)
-        {
+        } else if (p_basis_type == BASIS_LINEAR_SPLINE || p_basis_type == BASIS_CUBIC_SPLINE) {
           pressure_bocs->send_cg_info(p_basis_type, splines, spline_length);
         }
-      }
-      else
-      {
+      } else {
         error->all(FLERR,"Unable to find compatible pressure compute");
       }
     }
@@ -656,8 +652,7 @@ int FixBocs::read_F_table( char *filename, int p_basis_type )
     if (numBadVolumeIntervals > 0 && comm->me == 0) {
       error->message(FLERR, "INFO: total number bad volume intervals = {}", numBadVolumeIntervals);
     }
-  }
-  else {
+  } else {
     error->all(FLERR,"ERROR: Unable to open file: {}", filename);
   }
 
@@ -955,8 +950,9 @@ void FixBocs::final_integrate()
   tdof = temperature->dof;
 
   if (pstat_flag) {
-    if (pstyle == ISO) pressure->compute_scalar();
-    else {
+    if (pstyle == ISO) {
+      pressure->compute_scalar();
+    } else {
       temperature->compute_vector();
       pressure->compute_vector();
     }
diff --git a/src/DRUDE/fix_langevin_drude.cpp b/src/DRUDE/fix_langevin_drude.cpp
index 1b165c029aa..c67c729c7c1 100644
--- a/src/DRUDE/fix_langevin_drude.cpp
+++ b/src/DRUDE/fix_langevin_drude.cpp
@@ -108,9 +108,9 @@ FixLangevinDrude::FixLangevinDrude(LAMMPS *lmp, int narg, char **arg) :
 FixLangevinDrude::~FixLangevinDrude()
 {
   delete random_core;
-  delete [] tstr_core;
+  delete[] tstr_core;
   delete random_drude;
-  delete [] tstr_drude;
+  delete[] tstr_drude;
 }
 
 /* ---------------------------------------------------------------------- */
@@ -144,22 +144,22 @@ void FixLangevinDrude::init()
     else error->all(FLERR,"Variable for fix langevin/drude is invalid style");
   }
 
-  int ifix;
-  for (ifix = 0; ifix < modify->nfix; ifix++)
-    if (strcmp(modify->fix[ifix]->style,"drude") == 0) break;
-  if (ifix == modify->nfix) error->all(FLERR, "fix langevin/drude requires fix drude");
-  fix_drude = dynamic_cast<FixDrude *>(modify->fix[ifix]);
+  auto fdrude = modify->get_fix_by_style("^drude$");
+  if (fdrude.size() < 1) error->all(FLERR, "Fix {} requires fix drude", style);
+  if (fdrude.size() > 1) error->all(FLERR, "There must be only one fix drude");
+  fix_drude = dynamic_cast<FixDrude *>(fdrude[0]);
+  if (!fix_drude) error->all(FLERR, "Fix {} requires fix drude", style);
+
+  if (!utils::strmatch(update->integrate_style,"^verlet"))
+    error->all(FLERR,"Run style respa is not compatible with fix langevin/drude");
+  if (!comm->ghost_velocity)
+    error->all(FLERR,"fix langevin/drude requires ghost velocities. Use comm_modify vel yes");
 }
 
 /* ---------------------------------------------------------------------- */
 
 void FixLangevinDrude::setup(int /*vflag*/)
 {
-  if (!utils::strmatch(update->integrate_style,"^verlet"))
-    error->all(FLERR,"RESPA style not compatible with fix langevin/drude");
-  if (!comm->ghost_velocity)
-    error->all(FLERR,"fix langevin/drude requires ghost velocities. Use comm_modify vel yes");
-
   if (zero) {
       int *mask = atom->mask;
       int nlocal = atom->nlocal;
diff --git a/src/DRUDE/fix_tgnh_drude.cpp b/src/DRUDE/fix_tgnh_drude.cpp
index e15e865ce8c..bb0640fa45e 100644
--- a/src/DRUDE/fix_tgnh_drude.cpp
+++ b/src/DRUDE/fix_tgnh_drude.cpp
@@ -600,14 +600,20 @@ void FixTGNHDrude::init()
   // set temperature and pressure ptrs
 
   temperature = modify->get_compute_by_id(id_temp);
-  if (!temperature) error->all(FLERR,"Temperature ID for fix {} does not exist", style);
-
-  if (temperature->tempbias) which = BIAS;
-  else which = NOBIAS;
+  if (!temperature)  {
+    error->all(FLERR,"Temperature compute ID {} for fix {} does not exist", id_temp, style);
+  } else {
+    if (temperature->tempflag == 0)
+      error->all(FLERR, "Compute ID {} for fix {} does not compute a temperature", id_temp, style);
+    if (temperature->tempbias) which = BIAS;
+    else which = NOBIAS;
+  }
 
   if (pstat_flag) {
     pressure = modify->get_compute_by_id(id_press);
     if (!pressure) error->all(FLERR,"Pressure ID for fix {} does not exist", id_press);
+    if (pressure->pressflag == 0)
+      error->all(FLERR,"Compute ID {} does not compute pressure", id_press);
   }
 
   // set timesteps and frequencies
diff --git a/src/EFF/fix_temp_rescale_eff.cpp b/src/EFF/fix_temp_rescale_eff.cpp
index 5970c6cba73..0ca9c3e6e56 100644
--- a/src/EFF/fix_temp_rescale_eff.cpp
+++ b/src/EFF/fix_temp_rescale_eff.cpp
@@ -89,13 +89,15 @@ int FixTempRescaleEff::setmask()
 
 void FixTempRescaleEff::init()
 {
-  int icompute = modify->find_compute(id_temp);
-  if (icompute < 0)
-    error->all(FLERR,"Temperature ID for fix temp/rescale/eff does not exist");
-  temperature = modify->compute[icompute];
-
-  if (temperature->tempbias) which = BIAS;
-  else which = NOBIAS;
+  temperature = modify->get_compute_by_id(id_temp);
+  if (!temperature) {
+    error->all(FLERR,"Temperature compute ID {} for fix {} does not exist", id_temp, style);
+  } else {
+    if (temperature->tempflag == 0)
+      error->all(FLERR, "Compute ID {} for fix {} does not compute a temperature", id_temp, style);
+    if (temperature->tempbias) which = BIAS;
+    else which = NOBIAS;
+  }
 }
 
 /* ---------------------------------------------------------------------- */
diff --git a/src/EXTRA-FIX/fix_deform_pressure.cpp b/src/EXTRA-FIX/fix_deform_pressure.cpp
index a5b7b1fcb15..6d8bfbbe934 100644
--- a/src/EXTRA-FIX/fix_deform_pressure.cpp
+++ b/src/EXTRA-FIX/fix_deform_pressure.cpp
@@ -433,11 +433,14 @@ void FixDeformPressure::init()
   if (pressure_flag) {
     temperature = modify->get_compute_by_id(id_temp);
     if (!temperature)
-      error->all(FLERR, "Temperature ID {} for fix deform/pressure does not exist", id_temp);
+      error->all(FLERR, "Temperature compute ID {} for fix deform/pressure does not exist",
+                 id_temp);
 
     pressure = modify->get_compute_by_id(id_press);
     if (!pressure)
-      error->all(FLERR, "Pressure ID {} for fix deform/pressure does not exist", id_press);
+      error->all(FLERR, "Pressure compute ID {} for fix deform/pressure does not exist", id_press);
+    if (pressure->pressflag == 0)
+      error->all(FLERR,"Compute ID {} does not compute pressure", id_press);
   }
 
   // if yz [3] changes and will cause box flip, then xy [5] cannot be changing
diff --git a/src/EXTRA-FIX/fix_npt_cauchy.cpp b/src/EXTRA-FIX/fix_npt_cauchy.cpp
index 8eb6a80b6de..123cd6ca0a6 100644
--- a/src/EXTRA-FIX/fix_npt_cauchy.cpp
+++ b/src/EXTRA-FIX/fix_npt_cauchy.cpp
@@ -653,15 +653,20 @@ void FixNPTCauchy::init()
   // set temperature and pressure ptrs
 
   temperature = modify->get_compute_by_id(id_temp);
-  if (!temperature)
-    error->all(FLERR,"Temperature ID {} for fix npt/cauchy does not exist", id_temp);
-
-  if (temperature->tempbias) which = BIAS;
-  else which = NOBIAS;
+  if (!temperature) {
+    error->all(FLERR,"Temperature compute ID {} for fix {} does not exist", id_temp, style);
+  } else {
+    if (temperature->tempflag == 0)
+      error->all(FLERR, "Compute ID {} for fix {} does not compute a temperature", id_temp, style);
+    if (temperature->tempbias) which = BIAS;
+    else which = NOBIAS;
+  }
 
   if (pstat_flag) {
     pressure = modify->get_compute_by_id(id_press);
     if (!pressure) error->all(FLERR,"Pressure ID {} for fix npt/cauchy does not exist", id_press);
+    if (pressure->pressflag == 0)
+      error->all(FLERR,"Compute ID {} does not compute pressure", id_press);
   }
 
   // set timesteps and frequencies
diff --git a/src/EXTRA-FIX/fix_temp_csld.cpp b/src/EXTRA-FIX/fix_temp_csld.cpp
index 13ead5b3938..f60835ff394 100644
--- a/src/EXTRA-FIX/fix_temp_csld.cpp
+++ b/src/EXTRA-FIX/fix_temp_csld.cpp
@@ -138,20 +138,23 @@ void FixTempCSLD::init()
   if (tstr) {
     tvar = input->variable->find(tstr);
     if (tvar < 0)
-      error->all(FLERR,"Variable name {} for fix temp/csld does not exist", tstr);
+      error->all(FLERR,"Variable name {} for fix {} does not exist", tstr, style);
     if (input->variable->equalstyle(tvar)) tstyle = EQUAL;
-    else error->all(FLERR,"Variable {} for fix temp/csld is invalid style", tstr);
+    else error->all(FLERR,"Variable {} for fix {} is invalid style", tstr, style);
   }
 
   temperature = modify->get_compute_by_id(id_temp);
-  if (!temperature)
-    error->all(FLERR,"Temperature ID {} for fix temp/csld does not exist", id_temp);
-
-  if (modify->check_rigid_group_overlap(groupbit))
-    error->warning(FLERR,"Cannot thermostat atoms in rigid bodies");
+  if (!temperature) {
+    error->all(FLERR,"Temperature compute ID {} for fix {} does not exist", id_temp, style);
+  } else {
+    if (temperature->tempflag == 0)
+      error->all(FLERR, "Compute ID {} for fix {} does not compute a temperature", id_temp, style);
+    if (temperature->tempbias) which = BIAS;
+    else which = NOBIAS;
+  }
 
-  if (temperature->tempbias) which = BIAS;
-  else which = NOBIAS;
+  if ((modify->check_rigid_group_overlap(groupbit)) && (comm->me == 0))
+    error->warning(FLERR,"Cannot thermostat atoms in rigid bodies with fix {}", style);
 }
 
 /* ---------------------------------------------------------------------- */
@@ -170,7 +173,7 @@ void FixTempCSLD::end_of_step()
     modify->clearstep_compute();
     t_target = input->variable->compute_equal(tvar);
     if (t_target < 0.0)
-      error->one(FLERR, "Fix temp/csld variable returned negative temperature");
+      error->one(FLERR, "Fix {} variable returned negative temperature", style);
     modify->addstep_compute(update->ntimestep + nevery);
   }
 
diff --git a/src/EXTRA-FIX/fix_temp_csvr.cpp b/src/EXTRA-FIX/fix_temp_csvr.cpp
index 6b46629a997..9aeb51cfd8b 100644
--- a/src/EXTRA-FIX/fix_temp_csvr.cpp
+++ b/src/EXTRA-FIX/fix_temp_csvr.cpp
@@ -47,7 +47,7 @@ FixTempCSVR::FixTempCSVR(LAMMPS *lmp, int narg, char **arg) :
   Fix(lmp, narg, arg),
   tstr(nullptr), id_temp(nullptr), random(nullptr)
 {
-  if (narg != 7) error->all(FLERR,"Illegal fix temp/csvr command");
+  if (narg != 7) error->all(FLERR,"Incorrect number of arguments for fix {} command", style);
 
   // CSVR thermostat should be applied every step
 
@@ -75,8 +75,8 @@ FixTempCSVR::FixTempCSVR(LAMMPS *lmp, int narg, char **arg) :
 
   // error checks
 
-  if (t_period <= 0.0) error->all(FLERR,"Illegal fix temp/csvr command");
-  if (seed <= 0) error->all(FLERR,"Illegal fix temp/csvr command");
+  if (t_period <= 0.0) error->all(FLERR,"Illegal fix {} command period value", style);
+  if (seed <= 0) error->all(FLERR,"Illegal fix {} command seed value", style);
 
   random = new RanMars(lmp,seed + comm->me);
 
@@ -84,7 +84,7 @@ FixTempCSVR::FixTempCSVR(LAMMPS *lmp, int narg, char **arg) :
   // id = fix-ID + temp, compute group = fix group
 
   id_temp = utils::strdup(std::string(id) + "_temp");
-  modify->add_compute(fmt::format("{} {} temp",id_temp,group->names[igroup]));
+  modify->add_compute(fmt::format("{} {} temp", id_temp, group->names[igroup]));
   tflag = 1;
 
   nmax = -1;
@@ -124,17 +124,23 @@ void FixTempCSVR::init()
   if (tstr) {
     tvar = input->variable->find(tstr);
     if (tvar < 0)
-      error->all(FLERR,"Variable name {} for fix temp/csvr does not exist", tstr);
+      error->all(FLERR,"Variable name {} for fix {} does not exist", tstr, style);
     if (input->variable->equalstyle(tvar)) tstyle = EQUAL;
-    else error->all(FLERR,"Variable {} for fix temp/csvr is invalid style", tstr);
+    else error->all(FLERR,"Variable {} for fix {} is invalid style", tstr, style);
   }
 
   temperature = modify->get_compute_by_id(id_temp);
-  if (!temperature)
-    error->all(FLERR,"Temperature ID {} for fix temp/csvr does not exist", id_temp);
+  if (!temperature) {
+    error->all(FLERR,"Temperature compute ID {} for fix {} does not exist", id_temp, style);
+  } else {
+    if (temperature->tempflag == 0)
+      error->all(FLERR, "Compute ID {} for fix {} does not compute a temperature", id_temp, style);
+    if (temperature->tempbias) which = BIAS;
+    else which = NOBIAS;
+  }
 
-  if (temperature->tempbias) which = BIAS;
-  else which = NOBIAS;
+  if ((modify->check_rigid_group_overlap(groupbit)) && (comm->me == 0))
+    error->warning(FLERR,"Cannot thermostat atoms in rigid bodies with fix {}", style);
 }
 
 /* ---------------------------------------------------------------------- */
@@ -153,7 +159,8 @@ void FixTempCSVR::end_of_step()
     modify->clearstep_compute();
     t_target = input->variable->compute_equal(tvar);
     if (t_target < 0.0)
-      error->one(FLERR, "Fix temp/csvr variable returned negative temperature");
+      error->one(FLERR, "Fix {} variable {} returned negative temperature",
+                 style, input->variable->names[tvar]);
     modify->addstep_compute(update->ntimestep + nevery);
   }
 
diff --git a/src/MANIFOLD/fix_nvt_manifold_rattle.cpp b/src/MANIFOLD/fix_nvt_manifold_rattle.cpp
index d8b91fdda1a..c73438a7ef3 100644
--- a/src/MANIFOLD/fix_nvt_manifold_rattle.cpp
+++ b/src/MANIFOLD/fix_nvt_manifold_rattle.cpp
@@ -187,15 +187,15 @@ void FixNVTManifoldRattle::init()
   // Makes sure the manifold params are set initially.
   update_var_params();
 
-  int icompute = modify->find_compute(id_temp);
-  if (icompute < 0) {
-    error->all(FLERR,"Temperature ID for fix nvt/manifold/rattle "
-               "does not exist");
+  temperature = modify->get_compute_by_id(id_temp);
+  if (!temperature) {
+    error->all(FLERR,"Temperature compute ID {} for fix {} does not exist", id_temp, style);
+  } else {
+    if (temperature->tempflag == 0)
+      error->all(FLERR, "Compute ID {} for fix {} does not compute a temperature", id_temp, style);
+    if (temperature->tempbias) which = BIAS;
+    else which = NOBIAS;
   }
-  temperature = modify->compute[icompute];
-  if (temperature->tempbias) which = BIAS;
-  else                        which = NOBIAS;
-
 }
 
 void FixNVTManifoldRattle::setup(int /*vflag*/)
diff --git a/src/MC/fix_bond_swap.cpp b/src/MC/fix_bond_swap.cpp
index cc67a07ed2f..ff90b816957 100644
--- a/src/MC/fix_bond_swap.cpp
+++ b/src/MC/fix_bond_swap.cpp
@@ -136,13 +136,15 @@ void FixBondSwap::init()
   // require an atom style with molecule IDs
 
   if (atom->molecule == nullptr)
-    error->all(FLERR,
-               "Must use atom style with molecule IDs with fix bond/swap");
+    error->all(FLERR, "Must use atom style with molecule IDs with fix bond/swap");
 
-  int icompute = modify->find_compute(id_temp);
-  if (icompute < 0)
-    error->all(FLERR,"Temperature ID for fix bond/swap does not exist");
-  temperature = modify->compute[icompute];
+  temperature = modify->get_compute_by_id(id_temp);
+  if (!temperature) {
+    error->all(FLERR,"Temperature compute ID {} for fix {} does not exist", id_temp, style);
+  } else {
+    if (temperature->tempflag == 0)
+      error->all(FLERR, "Compute ID {} for fix {} does not compute a temperature", id_temp, style);
+  }
 
   // pair and bonds must be defined
   // no dihedral or improper potentials allowed
@@ -159,7 +161,7 @@ void FixBondSwap::init()
                    "topology because no angle_style is defined");
 
   if (force->dihedral || force->improper)
-    error->all(FLERR,"Fix bond/swap cannot use dihedral or improper styles");
+    error->all(FLERR,"Fix bond/swap cannot be used with dihedral or improper styles");
 
   if (force->special_lj[1] != 0.0 || force->special_lj[2] != 1.0 ||
       force->special_lj[3] != 1.0)
diff --git a/src/PLUMED/fix_plumed.cpp b/src/PLUMED/fix_plumed.cpp
index ec23e42ddb3..f88c0dce18f 100644
--- a/src/PLUMED/fix_plumed.cpp
+++ b/src/PLUMED/fix_plumed.cpp
@@ -272,6 +272,19 @@ void FixPlumed::init()
   // in a setup method
 
   for (int i = 0; i < 6; i++) virial[i] = 0.;
+
+  c_pe = modify->get_compute_by_id(id_pe);
+  if (!c_pe) {
+    error->all(FLERR,"Potential energy compute ID {} for fix plumed does not exist", id_pe);
+    if (c_pe->peflag == 0)
+      error->all(FLERR,"Compute ID {} does not compute potential energy", id_pe);
+  }
+
+  if (!c_press) {
+    error->all(FLERR,"Pressure compute ID {} for fix plumed does not exist", id_press);
+    if (c_press->pressflag == 0)
+      error->all(FLERR,"Compute ID {} does not compute pressure", id_press);
+  }
 }
 
 void FixPlumed::setup(int vflag)
diff --git a/src/REPLICA/fix_grem.cpp b/src/REPLICA/fix_grem.cpp
index 4571afdcbac..859c5f1bb31 100644
--- a/src/REPLICA/fix_grem.cpp
+++ b/src/REPLICA/fix_grem.cpp
@@ -117,11 +117,11 @@ FixGrem::~FixGrem()
   modify->delete_compute(id_press);
   modify->delete_compute(id_ke);
   modify->delete_compute(id_pe);
-  delete [] id_temp;
-  delete [] id_press;
-  delete [] id_ke;
-  delete [] id_pe;
-  delete [] id_nh;
+  delete[] id_temp;
+  delete[] id_press;
+  delete[] id_ke;
+  delete[] id_pe;
+  delete[] id_nh;
 }
 
 /* ---------------------------------------------------------------------- */
diff --git a/src/RIGID/fix_rigid_nh.cpp b/src/RIGID/fix_rigid_nh.cpp
index f628b639abe..9c51c0e3d21 100644
--- a/src/RIGID/fix_rigid_nh.cpp
+++ b/src/RIGID/fix_rigid_nh.cpp
@@ -247,7 +247,7 @@ void FixRigidNH::init()
   if (tcomputeflag) {
     temperature = modify->get_compute_by_id(id_temp);
     if (!temperature)
-      error->all(FLERR,"Temperature ID {} for fix {} does not exist", id_temp, style);
+      error->all(FLERR,"Temperature compute ID {} for fix {} does not exist", id_temp, style);
   }
 
   if (pstat_flag) {
@@ -285,6 +285,8 @@ void FixRigidNH::init()
 
     pressure = modify->get_compute_by_id(id_press);
     if (!pressure) error->all(FLERR,"Pressure ID {} for fix {} does not exist", id_press, style);
+    if (pressure->pressflag == 0)
+      error->all(FLERR,"Compute ID {} does not compute pressure", id_press);
 
     // detect if any rigid fixes exist so rigid bodies move on remap
     // this will include self
diff --git a/src/RIGID/fix_rigid_nh_small.cpp b/src/RIGID/fix_rigid_nh_small.cpp
index 3ee11e28d25..984f60e1f61 100644
--- a/src/RIGID/fix_rigid_nh_small.cpp
+++ b/src/RIGID/fix_rigid_nh_small.cpp
@@ -222,7 +222,7 @@ void FixRigidNHSmall::init()
   if (tcomputeflag) {
     temperature = modify->get_compute_by_id(id_temp);
     if (!temperature)
-      error->all(FLERR,"Temperature ID {} for fix {} does not exist", id_temp, style);
+      error->all(FLERR,"Temperature compute ID {} for fix {} does not exist", id_temp, style);
   }
 
   if (pstat_flag) {
@@ -237,7 +237,8 @@ void FixRigidNHSmall::init()
         int *dimflag = deform->dimflag;
         if ((p_flag[0] && dimflag[0]) || (p_flag[1] && dimflag[1]) ||
             (p_flag[2] && dimflag[2]))
-          error->all(FLERR,"Cannot use fix {} and fix deform on same component of stress tensor", style);
+          error->all(FLERR,"Cannot use fix {} and fix deform on same component of stress tensor",
+                     style);
       }
     }
 
@@ -260,6 +261,8 @@ void FixRigidNHSmall::init()
 
     pressure = modify->get_compute_by_id(id_press);
     if (!pressure) error->all(FLERR,"Pressure ID {} for fix {} does not exist", id_press, style);
+    if (pressure->pressflag == 0)
+      error->all(FLERR,"Compute ID {} does not compute pressure", id_press);
 
     // detect if any rigid fixes exist so rigid bodies move on remap
     // this will include self
diff --git a/src/fix_box_relax.cpp b/src/fix_box_relax.cpp
index cf8df7cd028..1362095a286 100644
--- a/src/fix_box_relax.cpp
+++ b/src/fix_box_relax.cpp
@@ -348,12 +348,20 @@ void FixBoxRelax::init()
   // set temperature and pressure ptrs
 
   temperature = modify->get_compute_by_id(id_temp);
-  if (!temperature)
-    error->all(FLERR,"Temperature compute ID {} for fix box/relax does not exist", id_temp);
+  if (!temperature) {
+    error->all(FLERR,"Temperature compute ID {} for fix {} does not exist", id_temp, style);
+  } else {
+    if (temperature->tempflag == 0)
+      error->all(FLERR, "Compute ID {} for fix {} does not compute a temperature", id_temp, style);
+  }
 
   pressure = modify->get_compute_by_id(id_press);
-  if (!pressure)
-    error->all(FLERR,"Pressure compute ID {} for fix box/relax does not exist", id_press);
+  if (!pressure) {
+    error->all(FLERR,"Pressure compute ID {} for fix {} does not exist", id_press, style);
+  } else {
+    if (pressure->pressflag == 0)
+      error->all(FLERR,"Compute ID {} for fix {} does not compute pressure", id_press, style);
+  }
 
   pv2e = 1.0 / force->nktv2p;
 
diff --git a/src/fix_langevin.cpp b/src/fix_langevin.cpp
index 7339ddada16..c032e73b84d 100644
--- a/src/fix_langevin.cpp
+++ b/src/fix_langevin.cpp
@@ -223,6 +223,15 @@ int FixLangevin::setmask()
 
 void FixLangevin::init()
 {
+  if (id_temp) {
+    temperature = modify->get_compute_by_id(id_temp);
+    if (!temperature)
+      error->all(FLERR, "Temperature compute ID {} for fix {} does not exist", id_temp, style);
+
+    if (temperature->tempflag == 0)
+      error->all(FLERR, "Compute ID {} for fix {} does not compute temperature", id_temp, style);
+  }
+
   if (gjfflag) {
     if (t_period * 2 == update->dt)
       error->all(FLERR, "Fix langevin gjf cannot have t_period equal to dt/2");
diff --git a/src/fix_nh.cpp b/src/fix_nh.cpp
index f2ad246611f..b56033d6d6f 100644
--- a/src/fix_nh.cpp
+++ b/src/fix_nh.cpp
@@ -654,14 +654,21 @@ void FixNH::init()
   // set temperature and pressure ptrs
 
   temperature = modify->get_compute_by_id(id_temp);
-  if (!temperature) error->all(FLERR,"Temperature ID {} for fix {} does not exist", id_temp, style);
-
-  if (temperature->tempbias) which = BIAS;
-  else which = NOBIAS;
+  if (!temperature) {
+    error->all(FLERR,"Temperature compute ID {} for fix {} does not exist", id_temp, style);
+  } else {
+    if (temperature->tempflag == 0)
+      error->all(FLERR, "Compute ID {} for fix {} does not compute a temperature", id_temp, style);
+    if (temperature->tempbias) which = BIAS;
+    else which = NOBIAS;
+  }
 
   if (pstat_flag) {
     pressure = modify->get_compute_by_id(id_press);
-    if (!pressure) error->all(FLERR,"Pressure ID {} for fix {} does not exist", id_press, style);
+    if (!pressure)
+      error->all(FLERR,"Pressure compute ID {} for fix {} does not exist", id_press, style);
+    if (pressure->pressflag == 0)
+      error->all(FLERR,"Compute ID {} for fix {} does not compute pressure", id_press, style);
   }
 
   // set timesteps and frequencies
diff --git a/src/fix_press_berendsen.cpp b/src/fix_press_berendsen.cpp
index 40dcdeeb104..c6fc0ad6026 100644
--- a/src/fix_press_berendsen.cpp
+++ b/src/fix_press_berendsen.cpp
@@ -266,17 +266,22 @@ void FixPressBerendsen::init()
   // set temperature and pressure ptrs
 
   temperature = modify->get_compute_by_id(id_temp);
-  if (!temperature)
-    error->all(FLERR, "Temperature compute ID {} for fix press/berendsen does not exist", id_temp);
-
-  if (temperature->tempbias)
-    which = BIAS;
-  else
-    which = NOBIAS;
+  if (!temperature) {
+    error->all(FLERR, "Temperature compute ID {} for fix {} does not exist", id_temp, style);
+    if (temperature->tempflag == 0)
+      error->all(FLERR, "Compute ID {} for fix {} does not compute a temperature", id_temp, style);
+    if (temperature->tempbias)
+      which = BIAS;
+    else
+      which = NOBIAS;
+  }
 
   pressure = modify->get_compute_by_id(id_press);
-  if (!pressure)
-    error->all(FLERR, "Pressure compute ID {} for fix press/berendsen does not exist", id_press);
+  if (!pressure) {
+    error->all(FLERR, "Pressure compute ID {} for fix {} does not exist", id_press, style);
+    if (pressure->pressflag == 0)
+      error->all(FLERR, "Compute ID {} for fix {} does not compute pressure", id_press, style);
+  }
 
   // Kspace setting
 
diff --git a/src/fix_press_langevin.cpp b/src/fix_press_langevin.cpp
index 8116d66c0ae..f3c3412fbd1 100644
--- a/src/fix_press_langevin.cpp
+++ b/src/fix_press_langevin.cpp
@@ -421,8 +421,11 @@ void FixPressLangevin::init()
   // set pressure ptr
 
   pressure = modify->get_compute_by_id(id_press);
-  if (!pressure)
+  if (!pressure) {
     error->all(FLERR, "Pressure compute ID {} for fix press/langevin does not exist", id_press);
+    if (pressure->pressflag == 0)
+      error->all(FLERR,"Compute ID {} does not compute pressure", id_press);
+  }
 
   // Kspace setting
 
diff --git a/src/fix_temp_berendsen.cpp b/src/fix_temp_berendsen.cpp
index ea2ffeb2c03..47091259c08 100644
--- a/src/fix_temp_berendsen.cpp
+++ b/src/fix_temp_berendsen.cpp
@@ -117,14 +117,16 @@ void FixTempBerendsen::init()
   }
 
   temperature = modify->get_compute_by_id(id_temp);
-  if (!temperature)
+  if (!temperature) {
     error->all(FLERR,"Temperature compute ID {} for fix {} does not exist", id_temp, style);
+    if (temperature->tempflag == 0)
+      error->all(FLERR, "Compute ID {} for fix {} does not compute a temperature", id_temp, style);
+    if (temperature->tempbias) which = BIAS;
+    else which = NOBIAS;
+  }
 
-  if (modify->check_rigid_group_overlap(groupbit))
+  if ((modify->check_rigid_group_overlap(groupbit)) && (comm->me == 0))
     error->warning(FLERR,"Cannot thermostat atoms in rigid bodies with fix {}", style);
-
-  if (temperature->tempbias) which = BIAS;
-  else which = NOBIAS;
 }
 
 /* ---------------------------------------------------------------------- */
diff --git a/src/fix_temp_rescale.cpp b/src/fix_temp_rescale.cpp
index 1a8993675a9..6578463a943 100644
--- a/src/fix_temp_rescale.cpp
+++ b/src/fix_temp_rescale.cpp
@@ -110,17 +110,20 @@ void FixTempRescale::init()
   if (tstr) {
     tvar = input->variable->find(tstr);
     if (tvar < 0)
-      error->all(FLERR,"Variable name {} for fix temp/rescale does not exist", tstr);
+      error->all(FLERR,"Variable name {} for fix {} does not exist", tstr, style);
     if (input->variable->equalstyle(tvar)) tstyle = EQUAL;
-    else error->all(FLERR,"Variable {} for fix temp/rescale is invalid style", tstr);
+    else error->all(FLERR,"Variable {} for fix {} is invalid style", tstr, style);
   }
 
   temperature = modify->get_compute_by_id(id_temp);
-  if (!temperature)
-    error->all(FLERR,"Temperature ID {} for fix temp/rescale does not exist", id_temp);
-
-  if (temperature->tempbias) which = BIAS;
-  else which = NOBIAS;
+  if (!temperature) {
+    error->all(FLERR,"Temperature compute ID {} for fix {} does not exist", id_temp, style);
+  } else {
+    if (temperature->tempflag == 0)
+      error->all(FLERR, "Compute ID {} for fix {} does not compute a temperature", id_temp, style);
+    if (temperature->tempbias) which = BIAS;
+    else which = NOBIAS;
+  }
 }
 
 /* ---------------------------------------------------------------------- */
diff --git a/unittest/commands/test_variables.cpp b/unittest/commands/test_variables.cpp
index c7686cbf12d..466dac17cce 100644
--- a/unittest/commands/test_variables.cpp
+++ b/unittest/commands/test_variables.cpp
@@ -731,8 +731,8 @@ TEST_F(VariableTest, LabelMapMolecular)
 TEST_F(VariableTest, Format)
 {
     BEGIN_HIDE_OUTPUT();
-    command("variable idx     index    -0.625");
-    command("variable one     equal    -0.625");
+    command("variable idx     index    -0.622");
+    command("variable one     equal    -0.622");
     command("variable two     equal     1.0e-20");
     command("variable three   equal    1.0e10");
     command("variable f1one   format    one \"%8.4f\"");
@@ -754,25 +754,25 @@ TEST_F(VariableTest, Format)
     command("variable g3one   format    one \"%5g\"");
     command("variable g3two   format    two \"%g\"");
     END_HIDE_OUTPUT();
-    EXPECT_THAT(variable->retrieve("one"), StrEq("-0.625"));
+    EXPECT_THAT(variable->retrieve("one"), StrEq("-0.622"));
     EXPECT_THAT(variable->retrieve("two"), StrEq("1e-20"));
-    EXPECT_THAT(variable->retrieve("f1one"), StrEq(" -0.6250"));
+    EXPECT_THAT(variable->retrieve("f1one"), StrEq(" -0.6220"));
     EXPECT_THAT(variable->retrieve("f1two"), StrEq("  0.0000"));
     EXPECT_THAT(variable->retrieve("f2one"), StrEq("-0.62"));
     EXPECT_THAT(variable->retrieve("f2two"), StrEq(" 0.0000000000000000000100000"));
-    EXPECT_THAT(variable->retrieve("f3one"), StrEq("-0.625000"));
+    EXPECT_THAT(variable->retrieve("f3one"), StrEq("-0.622000"));
     EXPECT_THAT(variable->retrieve("f3two"), StrEq("0.000000"));
-    EXPECT_THAT(variable->retrieve("e1one"), StrEq("   -6.2500e-01"));
+    EXPECT_THAT(variable->retrieve("e1one"), StrEq("   -6.2200e-01"));
     EXPECT_THAT(variable->retrieve("e1two"), StrEq("1.0000e-20    "));
-    EXPECT_THAT(variable->retrieve("e2one"), StrEq("-6.25E-01"));
+    EXPECT_THAT(variable->retrieve("e2one"), StrEq("-6.22E-01"));
     EXPECT_THAT(variable->retrieve("e2two"), StrEq(" 9.999999999999999E-21"));
-    EXPECT_THAT(variable->retrieve("e3one"), StrEq("-6.250000e-01"));
+    EXPECT_THAT(variable->retrieve("e3one"), StrEq("-6.220000e-01"));
     EXPECT_THAT(variable->retrieve("e3two"), StrEq("1.000000e-20"));
-    EXPECT_THAT(variable->retrieve("g1one"), StrEq("        -0.625"));
+    EXPECT_THAT(variable->retrieve("g1one"), StrEq("        -0.622"));
     EXPECT_THAT(variable->retrieve("g1two"), StrEq("1e-20         "));
     EXPECT_THAT(variable->retrieve("g2one"), StrEq("-0.62"));
     EXPECT_THAT(variable->retrieve("g2two"), StrEq(" 1E-20"));
-    EXPECT_THAT(variable->retrieve("g3one"), StrEq("-0.625"));
+    EXPECT_THAT(variable->retrieve("g3one"), StrEq("-0.622"));
     EXPECT_THAT(variable->retrieve("g3two"), StrEq("1e-20"));
 
     BEGIN_HIDE_OUTPUT();
@@ -782,7 +782,7 @@ TEST_F(VariableTest, Format)
     command("variable f1three  format  three %g");
     command("variable three delete");
     END_HIDE_OUTPUT();
-    EXPECT_THAT(variable->retrieve("f1one"), StrEq("-0.6250 "));
+    EXPECT_THAT(variable->retrieve("f1one"), StrEq("-0.6220 "));
 
     TEST_FAILURE(".*ERROR: Variable f1idx: format variable idx has incompatible style.*",
                  command("variable f1idx format idx %8.4f"););