Ok I had X3 Prod installed and working perfectly up to yesterday.  After installing the SampleTank 3.3 update this morning X3 will no longer open. I can't imagine why updating ST would cause a problem as ST 3.3 works just fine in Reaper. Sonar normally loads up with no project so it can't be ST causing a problem in a project.  I've done a reboot. I'm reinstalling X3 right now and the last resort will be a system restore and start all over.  Any other ideas ?

Don't have ST. Could an update to one program affect another yet leave similar programs untouched. Yes, the update may have affected a shared library used by only one of the programs. Usually crashes have some kind of message or minidump. Cakewalk support can read the dumps and help remove the guess work.

Ok a reinstall on top did no good.  I still get:
 

For the record the ST 3.3 works just fine in Reaper, Orion and FL Studio and does not cause any errors with those programs.  Also of interest Sonar X2 has stopped working as well.  Anybody know where the Plugin Lists are saved ? I'm going to try deleting them and see if Sonar will open then.

Arghhhh.  I give up.  I've just uninstalled X2 and X3 and will do a fresh install of X3.

If you have system restore enabled, the simplest method is restore the most recent restore point. Not sure why such would occur... Is X3 hanging on the VST scan? Is it possible that something is open using your interface in exclusive mode?

Complete Uninstall of both X2 and X3 and Reinstall of X3 did not work.  Now I'm doing a System Restore.

mettelus
If you have system restore enabled, the simplest method is restore the most recent restore point. Not sure why such would occur... Is X3 hanging on the VST scan? Is it possible that something is open using your interface in exclusive mode?

X3 scanned and passed the ST 3.3 update but there was a brief message popup about files or something.  It was too quick to read.  I was thinking that the custom Plugin List  might have gotten corrupted but you would think a full uninstall and reinstall would fix that issue.  I'll let you know how the system restore goes.........

Hi Teksonik,
This is probably of limited help for you, but I installed the ST3.3 update this morning and Sonar appears to be working fine. I know that's not much help, but it doesn't appear to be some kind of general bug with ST3 and Sonar.
 
Good luck,
Dean

Thanks that is a great help.  That eliminates a bug with ST/X3 so it's system specific.  I couldn't do a restore because my antivirus Bit Defender was blocking a file even when shut down.  But since the failed restore Sonar will now open and functions fine except now Melodyne won't show in Region FX even though it shows in other hosts.  I'm going out for awhile to clear my head and will tackle that problem later.
 
I think the Sonar issue had something to do with my AntiVirus but we'll see what happens after a fresh reboot.