Please stand on one leg :)
Reset and rescan?
Rinse and repeat...

Well I ignored the Red error and it seems to be working correctly.
 
Why would this problem happen for no apparent reason after these plugins have worked for so long?  Why would resetting and rescanning fix the problem?

vst3 version?

Phonic
Well I ignored the Red error and it seems to be working correctly.
 
Why would this problem happen for no apparent reason after these plugins have worked for so long?  Why would resetting and rescanning fix the problem?

I don't know please contact Slate Digital.
Again the VST Reset is here. You should be doing this after upgrading X3D, Cakewalk recommends this.
 

This got my attention as I LOVE the Slate VBC.  Luckily no problems to report (X3D 64, W7 64).

CakeAlexS - I have not just recently updated to X3D - I applied that patch as soon as it was available and did not have trouble until recently.  I have reset and rescanned the plugins multiple times since then.
 
This is what is so annoying - the plugins worked without issue until, all-of-a-sudden Sonar decides it doesn't like the VBC Rack and tells me it is incompatible.  So after installing the non-beta version of the plugins, the RACK works and now Sonar complains that the RED compressor is not compatible!  I ignored the error and it appears to work correctly, but I haven't put a lot of testing into the RED compressor since then.
 
It is always the most frustrating to trouble-shoot something that is inconsistent, such as the plugins working and then breaking for no apparent reason.

Phonic I remember some residual issues when beta or previous versions were installed and uninstalled.
Try this: uninstall & remove VBC plug-ins from your plug-in directories, and the related files in the ProgramData folder, then re-install VBC 1.0.1.6. There is a 1.1.0.8 and a beta 1.1.0.10 but seeing as those were addressed for Pro Tools users I think 1.0.1.6 should be fine. Also, I am a user of 1.0.1.6 as well on X3d with no issue.