I join scook in encouraging you to call tech support.
This shouldn't be happening.
Like others here, I have 64 bit and 32 bit versions of X3e(Studio) and SONAR2015(Professional) installed, as well as SHS6XL(It's dated, but it just plain works).
I do have an issue with both 64 bit X3e and SONAR crashing on save or exit, but that seems to be related to jbridge, or the fact that I am running a 64 bit system on 4Gb RAM. This happened before I installed the 32 bit versions, and actually the 32 bit versions are rock stable on my system.
At any rate, I can open and run any version at will.
I'm not suggesting that you don't have a legitimate problem, just answering the question.
Yes they can peacefully co-exist.
List your system specs in your signature. That may offer up some clues.
Good luck. I hope you get this resolved.