Sorry to hear you are having these problems.
You mention upgrading CrazyTalk before the crashing started. Does this mean CrazyTalk worked fine previously on the same computer?
If so, I would advise uninstalling CrazyTalk and reinstall the latest full version. This might help resolve the problem.
Sadly though CrazyTalk is now a legacy product and no longer receiving any further updates. This means that as Apple update their OS this will likely cause stability issues with CrazyTalk that won't be fixed. I personally have many favourite old programs that no longer run on modern operating systems (Windows). This means I faced two choices one was to abandon the older software or as in my case I kept an older computer running so that I could continue to use the software. Sadly its a decision we all run into at one time or another.
Please Note: If you have only recently purchased CrazyTalk 8 then you can request a full refund for it. Just make sure you make the request within 14 days after purchase.