If you get an error like this on Windows Server 2012 Hyper-V:
There was an error during move operation. Virtual machine operation failed at migration destination. Failed to access disk. The system cannot find the path specified.
For me this happened because I was using a differencing disk. The actual disk was called out in the error or I might not have caught it. In many cases, you’d be advised to do an export/import. This would obviously cause you to need to bring the VM offline. I was able to overcome this by copying the base of the differencing disk into the same location where I was live migrating:
This resolved the error.
It should be noted that it is still not a good idea to use differencing disks in production. Handy as they are for lab environments.