This has happened before. DP 64 had been working fine, and I have two instances of it working fine, but today I inserted another and it crashed CbB. So did DP 32. however, DP LE worked. 
 
I'm using a somewhat older version of CbB. I operate on the theory of It Ain't Broke Don't Fix It. Would updating to latest version solve it? 

Well, I updated to latest CbB, which I had not done in a while, and Dimension Pro 64 now works. But TTS-1 still causes a crash. I've seen some things about Bit Bridge; is this something I have to adjust or something?

BitBridge hosts 32bit VST plug-ins for use in 64bit CbB. The BitBridge server has been bundled with all versions of 64bit SONAR and now CbB. It has nothing to do with 64bit VST or DX plug-ins. BitBridge does not start up unless a project contains 32bit plug-ins.

TTS-1 is a DX plugin, right? so it could be to do with your windows Direct-X version? did they start failing after a windows update? anything in event viewer?

All Sonar Instruments seem to crash on mine and a friends computer. I am happy I only use the core and none of the plug-ins. Let us know if you find a fix.

Ah, that's right, it's DXi, not VSTi. So Bit Bridge is not a factor, as Scook said. This gives me something to go on. I'll check into my DX version. I have been doing security-only Windows updates, but there was a period a few months ago where I did the full roll-ups, hoping the Windows 7 update mess had been fixed. 
 
If it's a DirectX issue, I would think that lots of folks would be having problems with TTS-1, especially since it's the default midi synth for CbB. But I don't recall a lot of posts about TTS-1 not working. So it may be something about my setup specifically. Maybe I have an older DX version, and need to update it?

Note: I changed the title of the thread, since Dimension Pro is no longer causing crashes, only TTS-1.

I use TTS-1 all the time(everyday) because I am mainly midi (except for all vocals and all guitars) No issues with either app for me. Had win 8.qx64 and noew Win 10 Pro X64.   
Just adding to your info pool..............
 
BTW I have DXI Version 1.00 year 2004

PwalPwal hit it on the head, it had to do with Direct X. I installed the runtime updater from MS website (the first one listed), and TTS-1 now opens.