Same problem as with the OB-Xa to OP-Xa renaming:
I noticed that with the update to the new OP-Xa V, the resources folder in c:\ProgramData\Arturia\ (on windows ) /Library/Arturia/ (on MacOS) was also renamed to OP-Xa V.
So the old VST2/3 canīt access/find the included data and VST2 reported "not compatible" and the VST3 crashed.
I restored the OB-Xa V folder from my backup and both VST2īs OB-Xa V and OP-Xa V are working now,
the VST3 OB-Xa V are working again but if i drag and drop the new OP-Xa V VST3 to a session a OB-Xa V opened insead of the OP-Xa V.
For now I am fine with that because i can finaly open my old projects!
If you use the standalone version of the synth you have to restore the "C:\Program Files\Arturia\OB-Xa V" (windows/ on MacOS should be only one folder, see above) folder as well.