Opus froze while launching the duplicate file finder.
It never recovered, and in the end, I even had to use the power switch to restart the PC. I'm not sure that's ever happened before - usually, Task Manager is the most drastic measure needed. This makes me suspect the issue lies outside Opus. Could it be Filen.io? That's a cloud service I had installed just a few minutes earlier.
Crash dumps have been emailed.
Has to be something low-level if Task Manager can't kill the process. That means the process is stuck inside code that runs at the kernel level (which excludes all code from Opus itself).
From the dumps, the whole process seems to be frozen in the middle of doing a few things, so it's not certain which thing (if any) is the problem. But these are the ones I noticed:
A thread is refreshing the Quick Access list, and seems stuck deep inside a Windows API call when querying the file/folder attributes of one of the items in the list. (Can't tell which item it is, since it's not our code.)
Another thread is is querying the D:\ drive's statistics (amount of free space and similar).
Another thread started by GoogleDrive (drivefsext.dll) is doing something, but the DLL has no symbols so I am not sure what. May be a red herring; it only stands out to me because the callstack is fairly deep for an idle background thread, but that may be normal for it.
It could be that, since custom/cloud filesystems can install kernel-level components. If the D:\ drive is related to Filen.io, I'd say it's even more likely.