Ok Jonathan, thanks

Try this to see if it helps any (without doing anything to your plugins):
1) Uninstall Sonar X3c (or X3b, if that's what you have).
2) Run a registry cleaner (carefully) to clean out ONLY the Sonar remnants, not that this step absolutely needs to be followed.
3) Install X3a (the first copy you downloaded to install). Don't open X3a.
4) Now, upgrade directly to X3c.
5) Open X3c, double-check your Prefs and scan for your plug-ins.
 
From what I've seen, all projects should retain your plug-ins, and those plug-ins should be just as good as they were in X3b.
 
I would also caution to double-check that (in Preferences) that you do not have "Replace VST2 with VST3" checked, if you're using any VST2's when migrating your projects. Waves plug-ins are OK to be swapped out automatically, since X3b's release.
 
A considerable amount of testing was done for Waves plug-ins, with CLSID issues, and crashes for X3c. I have no issues now with Waves plug-ins in X3c unless I mix 32-bit with 64-bit, or VST2 with VST3's in the same FX Chain in ProChannel. I was one of the users more often able to have CLSID issues and crashes with Waves. Maybe this will help your projects survive the upgrade more seamlessly.
 
Lastly, IF this procedure helps, please let Cakewalk know. Maybe there is still an open issue moving directly from X3b to X3c that wasn't uncovered.
 
 

jb101
I think it stopped sometime in X1's lifecycle, Colin.

That was just for Quick Fixes, not full "letter" patches.   Although, the same process would be convenient. 

Thanks BRConflict. I might try that. I do have the VST2 to VST3 checked so that might be part of the problem I guess.

Thanks to all for this interesting and educational post.
Several years back, I had a terrific problem with SONAR 8.5
The program would go crazy in a lot of ways similar to conditions described in this post.
I'll spare you the details...
 
I contacted CW tech support ...studied as many relevant to my problem posts on the forum ...
I filed problem reports until finally, one tech asked a couple "odd" questions that seemed to call out the precise conditions / problems I was reporting
We were extremely thorough in ferreting out details...
 
Finally ...one day I got an email from that fellow ...he was really jazzed ...somewhere in Germany, a Roland tech was working on a completely different situation that produced conditions almost precisely as I described mine... somehow ...the interdepartmental information sharing process matched my problem with that one and VOILA!
 
I was sent a *new" version of S8.5 to install IMPORTANT NOTE..... only after I removed every possible trace of the version then currently on my computer. This process occurred several times as we refined the problem set down its' exact coding... I was happy to work with CW in this way ...and shortly after an update that addressed an old problem CW had for years.

It was a conflict with the OS (then it was XP 64) and CW. AN obscure, overlooked part of the programming that somehow had become a legacy in the basic operation of CW from Pro Audio days...
 
POINT: my problem was unique to the point most forum members passed it along as "my problem".
However ... a few like Cjay, Bitflipper, BAPU, Jim ROseberry were confident I wasn't nuts... together with CW tech support ...we figured it out.
 
This could be another of those situations. I know you will resolve your problem...

Thanks Again Y'all!