I purchased the X3 Producer upgrade (had X2 Producer installed) this weekend and after installing everything new seems to work fine. I can create a NEW project and record and play audio, MIDI etc. with no issues. My problem is I have a HUGE number of projects in X2 that I would like to bring into X3. When I load any of these projects X3 hangs. Audio engine will not start and anything I try to do hangs X3 and the PC for 2 to 3 minutes then after that if I try to reset Audio engine or do anything with the project it just hangs again. I can close that project and immediately create another NEW project and everything works fine again. I did NOT uninstall X2 (fortunately) so I can still access these projects but I would like to transition them into X3 to take advantage of some new features when mixing. What am I doing wrong?

Was the VST inventory reset and rescanned after upgrading? See http://www.cakewalk.com/S...ommended-for-Upgraders

I had NOT done that . . . I will when I get home today though and see if that makes a difference. THANKS for the heads up on this . . . I missed that little blurb.

And make sure you add the X3 effects and VST's to the X2 plug in manager scan path. You should be able to use all the same plug ins in both versions. 
And I was going to add make sure you have installed the 64 bit versions of both. The default on install is 32 bit and easy to miss that tiny dot. 

You may also wish to retain X2, so that you don't lose V-Vocal, which was dropped for X3 and replaced by Melodyne.
 
Lots of folks have done the above, myself included.
 
Bob Bone
 

Don't forget to update to X3E if you haven't already...

OK Boys - Thanks for the attempt but no dice getting any X2 project to open in X3. My workaround is to export the individual tracks and import them into X3 which allows me to use them but losing most settings. At least I don't have to re record everything.

This is not normal. It may be worth the effort of calling tech support to get it sorted out. Support lines will be open in an hour.

^^^^ This. It is indeed not normal.
 
Meanwhile, try opening in Sonar's safe mode to see what happens. 

Safe mode probably would have worked as my guess is the 32 bit version and plug in issues. 
 
And there was no need to export the audio as it is already stored in you audio folder for the X2 projects. 
Just drag and drop into a new project.