I have a case open with support on this already (Case # 02079640) but thought I'd mention it here in case anyone has come across this before.
For a particular backup chain, performing an FLR on a remote client causes the remote computer running the client to BSOD during the mounting process. Other backup chains can mount and FLR OK, so it's not a general issue. The same affected backup chain can be mounted as an Instant Recovery job, and boots OK (renamed and disconnected from the network) and I've been able to recover what I need from it, so the backup itself seems to be OK. Running the Veeam.Backup.Validator agains the backup job also succeeds (eventually! it's about 1.5TB to validate) so I'm guessing it's something about the mounted volume in the C:\VeeamFLR folder that the host doesn't like that's causing the BSOD.
I've seen two different BSOD's, having tried it a couple of times. Initially it was NONPAGED_AREA STOP Error 0x05, but the more recent ones have been BAD_POOL_HEADER STOP Error 0x19. At the time of the BSOD, the remote computer running the client reports in the Event Log an 'ntfs error Event ID 55: The file system structure on the disk is corrupt and unusable. Please run the chkdsk utility on the volume.' though I'm currently reading this as a red herring, and not taking it to literally mean that it's actually corrupted. It's obviously not happy about something in the mounted volume though.
The VM in question has recently had one of its smaller disks increased in size (300GB -> 350GB) which all went to plan and something we've done many times before, but this feels like it may be more than coincidence. To test this however, I have excluded this resized disk from the backup and re-run the job but it's still doing the same thing.
We have also recently upgraded from vSphere v5.5 to v6.0, which may also be related, but I can't see how this would affect only one backup job whilst others seem to mount and do an FLR job just fine..