So I had X2 installed and tried installing x3 which was a failure, so naturally I wanted to continue to use x2 until I could figure out a work around for X3. Upon loading some recent projects I just finished, it gives me errors on some the plugins not working properly, yet those plugins work fine in other applications and have worked fine before in Sonar. I am in the process of trying figure out what may have changed to get some of these plugins working again.

have you tried,
preferences / vst settings / rescan
 
every time you install sonar you need to run a scan of your plug ins.
if your set to automatic scan it should do this automatically.
I would try rescanning. if that doesn't work, try reset (right next to rescan)

thanks, I found a older version of x3 that didn't need that whole windows update c++ 2015 thing and installed that and it worked like a charm, everythings back. Thanks so much