Correct, the reason I mentioned copy protection is that all PACE products have a driver and a fault in the copy protection protocol will cause a BSOD because its in kernel mode. User mode programs cannot directly cause BSOD's since several windows versions ago. Anyway I wasn't trying to point fingers at your system but just provide a starting point for troubleshooting. You may be better served working with tech support on this issue since it might involve lengthy troubleshooting.
 
All VST scan does is load a VST and make a bunch of calls to it to query various properties. VstScan itself cannot cause a BSOD and neither can a plugin directly. However a plugin can access bad memory or do operations that involve drivers (in the case of PACE copy protection) which in turn can cause a crash. To trouble shoot this you have to take a subtractive approach. Craig's advice is excellent. Start with your VST Scan path pointing to only the Cakewalk plugins and let it finish that. Did that work? If so move on and add another vendor's plugins and let it rescan. Keep going till you find which plugin is causing the reboot. At that point we'll know the root cause of your problem. 

Also, if you get random crashes, try a memory test. Seriously, it is always a good thing to rule out. The number of times I've seen system randomly reboot, slow down, crash, act oddly due to RAM that had some minor errors, but was not completely failed, is quite high. Toss memtest86 at it when you have some free time and see what it says. You might have a memory error.

Noel Borthwick [Cakewalk]
Correct, the reason I mentioned copy protection is that all PACE products have a driver and a fault in the copy protection protocol will cause a BSOD because its in kernel mode. User mode programs cannot directly cause BSOD's since several windows versions ago. Anyway I wasn't trying to point fingers at your system but just provide a starting point for troubleshooting. You may be better served working with tech support on this issue since it might involve lengthy troubleshooting.
 
All VST scan does is load a VST and make a bunch of calls to it to query various properties. VstScan itself cannot cause a BSOD and neither can a plugin directly. However a plugin can access bad memory or do operations that involve drivers (in the case of PACE copy protection) which in turn can cause a crash. To trouble shoot this you have to take a subtractive approach. Craig's advice is excellent. Start with your VST Scan path pointing to only the Cakewalk plugins and let it finish that. Did that work? If so move on and add another vendor's plugins and let it rescan. Keep going till you find which plugin is causing the reboot. At that point we'll know the root cause of your problem. 

Just for kicks, since I'm at work, I loaded X3 onto my laptop, which I use for remote recording with Audition (I'll take it off when I get home -- I don't want to violate my license).  The laptop has all the same VSTs as my home editing machine, except one.  As with my home machine, it did NOT include Izotope Ozone in Audio Plug-in browser.  I opened the Plug-ins Manager and rescanned from there.  This time it found Ozone, though it still did not appear in Plug-in Browser.  Then I did what I had tried to do on my home machine that caused the crash, i.e. I opened the X3 Producer Effects preset in the Plug-ins Manager and manually added Ozone along with Celemony Melodyne.  No crash this time, and now, FINALLY, Ozone appears under Synths as FX in the Browser.  This isn't the best place for it but, at least, it shows up.  The Celemony VST3 also appears (correctly) under Pitch/Time.
 
X3 clearly has a headache with Ozone, which I use extensively for mastering.  Simply scanning will NOT work, nor will re-setting and re-scanning.  The only way to get it to appear is by manually adding it to the X3.   

Sycraft
Also, if you get random crashes, try a memory test. Seriously, it is always a good thing to rule out. The number of times I've seen system randomly reboot, slow down, crash, act oddly due to RAM that had some minor errors, but was not completely failed, is quite high. Toss memtest86 at it when you have some free time and see what it says. You might have a memory error.

I don't get random crashes.  I got a single crash when I attempted to do one thing.  I agree, though, that the most common cause for random crashes (other than malware) is memory.

Are all your plug-ins 64-bit?

mrdrwest
Are all your plug-ins 64-bit?

Nope.  It's about a 70%-30% split between 64-bit and 32-bit.

PTravel
X3 clearly has a headache with Ozone, which I use extensively for mastering.  Simply scanning will NOT work, nor will re-setting and re-scanning.  The only way to get it to appear is by manually adding it to the X3.   

 
Are you using the VST3 version of Ozone or VST2? QA has tested Ozone and there were no problems.
I have Ozone VST2 at home and it scans and works fine in X3.

Noel Borthwick [Cakewalk]

PTravel
X3 clearly has a headache with Ozone, which I use extensively for mastering.  Simply scanning will NOT work, nor will re-setting and re-scanning.  The only way to get it to appear is by manually adding it to the X3.   

 
Are you using the VST3 version of Ozone or VST2? QA has tested Ozone and there were no problems.
I have Ozone VST2 at home and it scans and works fine in X3.

VST3 version.

I would start by making sure the Fast Track Ultra is showing correctly under driver settings.  IOW, don't assume nothing has changed from your last setup.  After the upgrade, my interface changed to a generic ASIO driver, with the proper ones visible below but grayed out.  Once I switched to WASAPI (instead of ASIO), the normal drivers were accessible again, and I just manually unticked "generic" and ticked the correct ASIO drivers.  After hitting apply, this affected a bunch of other settings as well.
 
If your interface driver looks okay, then I'd move on to the plugins.  Try one or more of these:
 
- Under Edit-pref, uncheck "Replace VST2 Plug-ins When Opening Projects".  Apply.  Go back in and rescan plugins.  What happens?
- Under same place, uncheck "Rescan failed plugins"  Apply.  Go back and rescan.. What happens?
- If scans okay after doing the above, check the excluded plugins list.  Is Ozone there?
- Use shift key to open Sonar in safe mode (bypasses plugins).  What happens?
 
Point being, if it is a plugin causing a problem, you can isolate it, then once you are sure everything else scans okay, you troubleshoot the plugin (Make sure you have the latest version, or you may need to reinstall it, etc).
 
Good luck.

I'm learning alot reading this thread!