After painstaking hours trying to troubleshoot why several projects kept locking up, my bandmate and I tracked it down to Dimension Pro looped/groove drum patterns. (I'm not sure of exactly what they're called, but it's the Dimension Pro drum sounds that play the built-in sequenced patterns when you hold down a key in the lower octave of the keyboard.)
 
If we had one of those loaded in a project (even if we had just "auditioned" those sounds/patterns without actually having them triggered via midi in a project), then when playing back the project the system experiences various weird "lock up" situations, in which the transport and all other control of Sonar stopped working. There was no way to recover from the problems or exit Sonar gracefully, and we'd have to Ctrl-Alt-Del to shut down Sonar and then restart.
 
We were able to replicate the problem on two different Windows 8.1 systems both using ASIO, with different audio interfaces (Mackie Mixer and M-Audio M-Track Plus) and several different projects. Through process of elimination and numerous restarts of Sonar and some cold re-boots, we tracked it down to the Dimension Pro loop/groove drum patterns. We've had no further problems with "lock ups" or crashes since removing the instances of Dimension Pro that had those patches loaded.
 
Has anyone else experienced this problem?
 
BTW, I've submitted the info above as a bug/problem report, but wanted to post here in case anyone else is experiencing frustrations with this same issue. Hope that's appropriate (I'm a long time Sonar users, but new to posting here).

I have an outstanding problem with an Anderton program, but that's the only problem I've had with Dim Pro

huh! Just for giggles, tried your scenario, jfochtmann. Yep, the 2nd Dim Pro groove patch I tried playing back, locked Sonar up something fierce. I'm going to have to cold boot, which I haven't had to do in a long while. So I'm ending this post to reboot.

Sadly, these presets has been observed for years now to be problematic.
The situations can vary depending on the way they are used. 
Standalone mostly goes without issues, for you can restart. In the sequencer, the bit depth and sample rate of your Project Template can affect performance results. Lockups/crashes can cause you to loose work if not actively saved. My best resolve is to freeze tracks or create a groove clip with about the flaky presets.
Dim Pro went from DXi 32 bit to VST 64 bit now over the years.
 
Will be interesting to see how these perform with the new Raptor Pro.......... 

Yup. I reported this problem years ago and the work around according to tech support was to copy the drum samples to Dimension LE and play the loops from there. Never did so I don't know if it works or not. 

Thanks for all the quick feedback everyone. I've now located some of those prior discussions on this topic (don't know how I missed seeing them when searching yesterday):
(2015)
(2014)
(2012, including Geo524's previous sharing of the workaround--sorry to make you restate it again here)...
 
Ahh, looks like I can't post links yet for some reason (maybe I don't have enough posting history?). Anyway I found those older discussions by searching in Google under "sonar crash dimension pro drums"

I hope Rapture Pro will be better supported than Dimension Pro or Rapture in future. The state they were left in was not good. Cakewalk you now have a clean slate, but you still have yet to fix Z3TA+2 and pro channel plugin issues (which are still for sale).

jfochtmann
Thanks for all the quick feedback everyone. I've now located some of those prior discussions on this topic (don't know how I missed seeing them when searching yesterday):
(2015)
(2014)
(2012, including Geo524's previous sharing of the workaround--sorry to make you restate it again here)...
 
Ahh, looks like I can't post links yet for some reason (maybe I don't have enough posting history?). Anyway I found those older discussions by searching in Google under "sonar crash dimension pro drums"

Hi and welcome to the forum.
Yes, you need 25 posts to be able to do link shortcuts.   As far as Dim Pro goes, my experience is about the same as the other posters.

Confirmed. There are certain loops that appear to contain poison 
 
As to the issue with the Gold Top, one person told me that they had issues with it that went away after re-installing Dimension Pro. That's pretty anecdotal, and only one person...but who knows. That probably won't fix the "poison loop" issue, though.

Anderton
Confirmed. There are certain loops that appear to contain poison 
 
As to the issue with the Gold Top, one person told me that they had issues with it that went away after re-installing Dimension Pro. That's pretty anecdotal, and only one person...but who knows. That probably won't fix the "poison loop" issue, though.

I have an open case on that one.  I sent updated scenario tests to "Mike" several days ago, but haven't heard back.  It seems I'm an isolated case or nobody else uses GT at 48K  ;)
 
I'm letting it ride until I get Rap Pro installed.  My plan is to completely uninstalled Dim Pro and Rapture and their content.  Maybe the GT goodies will work after reinstalling.
 
It is very strange though ... I haven't had problems with with anything else in Dim Pro.