The file could not be written successfully

After updating to WL9.1 I get this message every time I open a project or try to save something. After closing and restarting WL, opening last project everything is there, but the plugin GUI’s are out of wack.

Forcing WL to generate new ini / settings files does not change this.

Anybody else experiencing this?
The file could not be written successfully.jpg

This is probably because your preferences cannot be saved.
Make sure this path, on Mac, is not read-only:
/Users/YourName/Library/Preferences/WaveLab Pro 9/

No, that’s not it