I got this cryptic warning loading a project of mine:
After some head scratching and a diff check in Notepad++ I figured out that the recent 0.7.0 update to bkFX (
https://www.kvraudio.com/forum/viewtopic.php?t=369138 ) was the culprit. I have an envelope changing the LFO waveform of bkDualFilter, and that envelope was completely missing. Seems like the 0.7.0 update changed this param to non-automatable. Reverting to 0.6.0 brought the LFO waveform envelope back.
Now the point of this post is that the error message is quite misleading. The project was last saved in March 2022 in 6.51, and last opened in 6.62rc3 today. Also, the error message doesn't at all specify which parameter (or even plugin) this concerns. This might be a somewhat rare edge case, but a more informative error message would be nice
(not really sure if this should be in bug reports tbh)