So I'm working with two new clients in my studio when, for no apparent reason, Sonar repeatedly froze when trying to open existing projects.  Out of the dozen or so I attempted to open only ONE project would open, and everything seems to function as normal.  Also I can create new projects and record and mix.  Nothing changed hardware wise in the pc, and I'm running out of ideas before trying to reinstall.  Anyone else had this issue?
 
Thanks for your time.
 
Leon

Make sure you are on X1D. Try opening in safe mode:
http://forum.cakewalk.com/Open-Sonar-in-safe-mode-Solved-m2524512.aspx
 
http://www.cakewalk.com/Documentation?product=SONAR%20X2&language=3&help=Troubleshooting.13.html
 
Cheers...

I concur with Alex, on the idea of opening in Safe Mode.  
 
It sounds like some sort of 3rd-party plugins problems, and/or issues with maintenance of either Sonar or Windows maintenance.
 
Bob Bone
 

I'll say one thing. You either use Sonar 8.5 or X3e if you want to avoid any weirdness. My 2.5 cents worth. Upgrades have been almost free to registered owners so there is no reason anyone should be using the older "buggy" X versions anymore. Sorry that's not exactly helpful, but just my Sonar wisdom and Advice. I'd sympathies if you where still using 8.5 because that too was rock solid. X1 was a bugger...