I was feeling brave and taking all due precautions.
This is definitely where the issue lies. I followed your instructions here except I renamed my CLSID key to “CLSID-old”, closed regedit and started Scrivener with the log function. Scrivener launched properly. I closed Scrivener and reopened regedit to find I had a new CLSID key with the Scrivener specific key in it. See screen shots. Process ID name of the Scrivener key is: Rnvrcs and appears to have the same data.
No, not on this machine or on a machine with Scrivener installed.
I can make Scrivener break on that user by swapping the CLSID key names. It might be interesting to make a copy and then remove the other software CLSID entries to see if one of them fixes the Scrivener key; however, I think that it won’t make much of a difference. The only two keys I have found between the two users that are common are both for Grammarly:
and -
HKEY_CURRENT_USER\Software\Classes\Wow6432Node\CLSID{4BE56754-B616-4998-B825-D16983AEE1B2}
In my working Scrivener user, those two keys are present. In my previously non-functional Scrivener user they were there, but not in the new functional version of CLSID. Grammarly does work properly for the user without those two keys.