I just purchased Sonar X3 Producer last month so am still learning a lot! Something odd is happening with Pentagon. I added it using the + sign as a Synth. If I delete the Pentagon Synth - using the X sign to delete, it immediately crashes Sonar X3. I've shut down Windows 8.1 and tried this a few times - same thing happens. Is there a better way to delete Pentagon that I should know about?

Does SONAR throws up a dialog indicating the faulting module before shutting down? If this is not happening, there may be something in the Windows Event logs which may be helpful. SONAR must be running as administrator otherwise I don't believe Pentagon would load. There is a context menu which pops up when right-clicking a synth rack entry. It has a delete option but I would expect it to call the same routine the X does.

There is something screwed up with one of the simulator files (it sits right below the Pentagon I logo) if you hover overit and click it gives you a dropdown of what's available. I think it is one of the "Valley" speaker sims. For me it would completely overload the input of my soundcard and my whole system would crash. Maybe it has something to do with that? Ijust avoid those patches or choose another sim BEFORE I play any notes.

Some patches using the Valleys1-3 are indeed messed up.
 
You can 'fix' them by turning off the simulator and saving them back.  I did.  But then, I don't even know what these simulators do, so it wasn't a great loss.
 
 

I don't recall the longstanding Valleys Simulator bug crashing SONAR. For some it would stop audio in the project; others received a very loud blast of noise. I get the blast of noise. Not running Win 8.1, the behavior may be different, IDK. Doubt this bug is causing the delete problem.

Yeah ,I'm just taking a stab in the dark on that one, but for me, it did more than cause dropouts or audio engine stopping, it literally froze my sound card and I would often be unable to do anything, not even move my mouse. No BSOD, but plenty scary.

Here is a current an related thread http://forum.cakewalk.com/FindPost/3100551