diff --git a/ui/main_dialog.py b/ui/main_dialog.py
index b6c7830..01c5dc1 100644
--- a/ui/main_dialog.py
+++ b/ui/main_dialog.py
@@ -260,6 +260,9 @@ def _process_node_recursive(self, node, parent_node):
                 ):
                     # Unsupported QgsMapLayerType
                     continue
+                if not child.layer().isSpatial():
+                    # exclude no geometry layers such as CSV files
+                    continue
 
             else:
                 raise Exception("Unknown child type")