I opened an old VEP5 project saved it as VEP6. Stopped and restarted VEP6 and opened that new project again.
1st time, it froze solid "loading channels... 90%
Second time: it got thru
Third time: it got thru
Fourth time: it got thru
I then modified a Vienna Suite EQ filter on the violas in one instance, and saved the preset in the same project.
Saved the project, stopped VEP6, restarted, re-opened the project.
It got thru and the preset was loaded correctly.
Don't know if it fixes all other issues mentioned by other members but at this point I'd like to say tks cum laude to the dev & support teams for a quick turnaround and efficient fix!
(nb: beforehand, VEP6 would get stuck (sometimes at 76%, sometimes 90%, sometimes 16%) loading one of the instances in the project. It rarely giot to load the entire project.)