I wish I had a clue as to what it could be. My Braintree update went smoothly
except that whenever I clicked on Platinum ProChannel Collection (which was lit yellow), CCC would crash with what I assume is the same error message as yours. This has been consistent behavior, and if I tried to roll back, right-clicking would also cause the crash. So I continued updating all the other elements, which all worked as expected.
When I opened SONAR for the first time after all the updates were complete, it crashed (my first since installing Platinum, interestingly enough) with an error message that indicated REmatrix was the source of the problem. As it turned out, I had created a temporary .RIR file to evaluate Dan's impulses and renamed the original, so there was a "rogue" folder. Doing this had never caused problems before, but when I moved the rogue folder, SONAR opened normally. However, clicking on Platinum ProChannel Collection still causes the CCC to crash.
I put the rogue folder back in, and SONAR again opened normally and has worked fine ever since. Everything has been updated, and Bark of Dog is in the ProChannel. So nothing really needs to be updated, but I wanted the yellow ProChannel Collection light to turn green
I wonder if the crash upon clicking on Platinum ProChannel Collection was related to REmatrix in some way. A dump was generated and sent to Cakewalk; we'll see if they can figure out why it's happening. If so, whatever is causing the problem with that one element might be related to the overall problem you're having.
In your case, the only thing that comes to mind is that CCC is trying to do something to your system, and an anti-virus program is preventing it from happening. I have Windows Defender running in the background, and forgot to disable it when downloading and running the CCC. I'm going to try turning Defender off, re-installing and running CCC with all anti-virus routines disabled, and seeing if that solves the ProChannel update issue.
It does not seem like this is a common problem, or there would be more comments because a crash is a pretty obvious issue. Hopefully I can figure out what my CCC problem is, and even though it's minor compared to yours, perhaps a solution could help resolve yours.