GPK File error after Save As... [WL Pro 10.0.40]

I hqave an issue using WaveLab Pro 10.0.40. After I save modified file as new file and if I open old file, WaveLab cannot recreate peak file (gpk). Also preview in FileBrowser gives a message:
This file could not be accessed. It is already in use by this application or another.

All files closed. No other applications use this nor wav file.

The sequence:

  1. I open wav file, WaveLab generates peak file.
  2. Use Process->Loudness->Youtube2019 - it does its job okay.
  3. Save As… new file myfile-max.wav.
  4. I close all opened files.
  5. In FileBrowser I click on old file and WaveLab gives a message “… This file could not be accessed…” and it mentions peak file *.gpk
  6. I click on new file and it plays a preview okay.
  7. I doubleclick on old file, WaveLab opens it, but gives a little text in the middle of waveform - “Cannot create peak file”.
  8. I press Spacebar and it plays okay.
  9. I restart WaveLab and all is okay - can see waveform in both preview and opened file.

So it looks like after “Save As…” command WaveLab lost the gpk file attached to old file since there is active new modified data.
Of course the restart of programm doesn’t really break any bone, but every error reminds me for what I paid to have Pro version.

I can’t reproduce this problem. Try toggling this option, to see if that makes a difference: