I would suspect your hard drives have developed bad areas. They just don't make em like they used to.
Run cmd as administrator and start a chkdsk /r on your drives that sonar uses. Prolly should backup first.
It would all take a while. If you fin any bad areas, they only multiply over time so the next step is to then clone your ailing disk to a new one with say, Acronis true image.

I've upgraded from Sonar Pro to Platinum and my Splat runs better than my Pro was. You should restore back to where everything worked and go from there. Second make it a habit not to have other programs running in the background. Turn your Antivirus off, they either use or deter particulars needed for Sonar. And use plugins that are 64 bit versus 32 bit, which will also cause your 64 bit version to crash.

Hopefully you have system restore points enabled. I would definitely recommend going back a month and checking what programs were modified with the restore point you choose (any data files you have made will not be affected). This will also give you the data point others here are trying to understand... if you restore to a month ago when things worked, but now they do not, it is a good indicator of failing hardware (somewhere).

I had huge issues until the Bakers helped me uninstall all the old versions and do a full reinstall of Platinum. It was less painful than it sounds and voila, 90% of the issues were suddenly gone.

Ok guys... I have been a faithful Sonar user for many years.   Craig, for the most part Sonar was working. It crashed occasionally.  The biggest issue was crashing projects with Slate VST's.   I have to leave to go to church. Maybe God will help!

There are known compatibility issues with Slate plugins. Please contact the vendor to resolve these since we have no control over that. If the vendor finds a problem with SONAR's vst compatibility they should contact us after troubleshooting it first on their end.

stevee9c6
Ok guys... I have been a faithful Sonar user for many years.   Craig, for the most part Sonar was working. It crashed occasionally.  The biggest issue was crashing projects with Slate VST's.   I have to leave to go to church. Maybe God will help!

God uses Pro Tools. ;-)
I know cause he does at my church.

Even God can't solve 3rd party VST problems :)

Noel Borthwick [Cakewalk]
Even God can't solve 3rd party VST problems :)

I think He was busy, bringing people back to life, healing the sick....creating EDM loops and I think is working on a vocal simulation/replacer.

If you turn your antivirus off - also disconnect your computer from the internet.
I see that you are running at 4.5 ghz.  Is that an overclock?   Is your CPU or memory overheating?
I would think that a CPU running less than 4.5 (like 4.0) would still be very sufficient and not place so much stress on the CPU.  But the memory setting is important as well.

Just some thoughts that might help.