What means "invalid PPS index" ?

[DonaldFaQ]

In some cases i will inject a converted P8 RPU (from P5) into the HDR stream, i become this message:

ERROR. invalid PPS index.

What means this and is there a way to fix this problem?

[quietvoid]

It's an error in the HEVC bitstream parsing.
The PPS is probably missing from the file so it can't parse correctly.

There's no fix outside ignoring NALs, you need to fix the files.