Heads up, all threat hunters.
I recently encountered a problem with several customers using ThreatHunter. It happened that mounting the file system needed to crawl the system didn't work.
However, mounting the file system for a single file restore worked fine.
It turned out to be a small bug in the code and there is already a private fix for this, and it will be included in the next release:

So if you encounter this problem, just file a case with Veeam support and get your private fix in the meantime. According to the registry keys that come with the fix, it seems to have something to do with certificate revocation.
However, everything works as expected once the fix is in place.