To resolve this error you can manually extend the VSS timeout by editing the following registry key:
Change value to 12000000 (2*10*60*1000 = 20 mins).
The default for the timeout period is 10 mins so hopefully doubling this will give enough time to complete the snapshot.
If this isn’t present, you will need to manually enter the registry key. It is a DWORD 32-bit key.
See below for an example: