I've recently migrated from Sonar X1 to Sonar X2, (including all of the updated patches for Sonar X2).
This includes moving to a new PC with upgraded CPU and RAM.
 
I'm having a lot of trouble migrating some projects that used to open fine in Sonar X1.  I was careful to keep my Audio together with the project files.  When I first open the project file it asks me to point to one of my audio files that it couldn't find, so I point it to the appropriate folder for the audio.  Then Sonar attempts to open the project and it spins forever, never finishing, then I am notified that Sonar is taking nearly 100% of the CPU.  This doesn't seem right at all.  What could be the problem?  One would think that it would just invoke an error message if it couldn't find the file or something rather than spinning forever and never opening the project.
 
Any ideas on what could be wrong?  Is there some kind of Windows7 OS setting that is causing this trouble?
I'm using Windows7 Professional in the new PC and I used Windows7 Home Premium on the old PC where the same project opened with no problem in Sonar X1.
 
Thanks,  --Jim Pfeifer

Can't say for sure - but there are times when Sonar does take a long time to load. Usually this is when something is running in the background - you can tell if the drive indicator light on your PC is on/blinking.
 
Another possibility is that a VST is displaying a windows dialog box, but it is underneath the Sonar window.
 
If neither drive activity nor a hidden dialog, then it may be a genuine crash.

Could be a misbehaving plug-in, try loading in safe mode. Hold the SHIFT key while loading the project.

You don't by chance have a VS-700 do you?  There is a particular bug with that.

Please update your footer like mine (we don't know what you are running). Cheers...

Here is my setup below:
 
Sonar X2a Producer Edition (64-bit), Windows7 Professional (64 bit), Lenovo PC (Intel i7 Core,  12GB RAM, 2x WD hard drives 2TB 7200rpm 64MB cache),  Focusrite Saffire Pro 24 (Firewire), PreSonus Faderport, Virtual Instruments: Spectrasonics Omnisphere & Stylus RMX, Vir2 Mojo Horns, EWQL Symphonic Orchestra Gold, Z3ta+2
 
--Jim 

Mine has done that and it was mostly plug ins - esp. 32 bit on a 64.  Plus ilok had some problems when they updated.  As said above, open w/ shift and then you can step through the plugs and see which is misbehaving.

+1
 
And latest mix control software here:
http://uk.focusrite.com/firewire-audio-interfaces/saffire-pro-24/downloads
 
and please check your event viewer for errors.
 
Cheers

Great!  Thanks for the tips.  I'll check it out to find out what is causing the stall.  It's happening a lot on the projects that I've imported from my other PC, even on my projects where it only contains a single stereo track in the project for mastering a final mix, using only the iZotope Ozone plugin across the Master bus.   I'll definitely check into the updated mix control software as well.
 
--Jim 

Given your set-up, I agree with the advice above.  THis is probably plug related.
 
One particular problem Sonar has is that a dll file for a plug in often has both a 32 and 64 bit version and they are usually named the same and put in different folders.  If Sonar finds the wrong one first or finds both, it can get confused.  Loading with Shift held down as said above allows you to say yes or no to plug ins one by one.  That can take some time and effort to find which one is causing the problem, but it will get you there.
 
I usually say NO to half the plug-ins and YES to the other half so I at least know which half has the problem plug-in.  Then I make another run only allowing a few of the bad half in, etc.