VMWare 10 with Windows 7+8 x64 hosts and guests.
I often suspend the VM and restart the host, then restart the VM, only to be told that "an error occurred while restoring the VM state". It happens on different machines, with different VMs, about once a week or so. It also happens now and then when I try to go to previous snapshots (eg Autoprotect), some snapshots work fine, others give the same error and wont resume. I can't see anything obvious from the log files, just the "msg.checkpoint.restoregroup.failed" with restore failing at the last minute. It's never clear why this happens, and it doesn't seem to be related to the specific install or guest. So it's a big question mark.
The advice given is usually to delete state and checkpoint data, effectively hard resetting the machine. If it was very rare, I'd be happy, but it's an inconvenience to suspend a VM and then find it won't resume, or use autoprotect snapshots and not know if they'll work on the occasions you want to revert to them. I like reliability in my tech 
It's likely that other people have tried at one or another time to fix an important snapshot or suspended VM, and can describe what they know about it.
As the problem seems to recur periodically, I'd like to ask if people know ways to debug or repair a "restore state error" suspended VM, and how I can identify exactly what's caused resume to fail on these occasions, so I can fix it in future.