If the VSS writers employed during the NetVault Backup snapshot process do not finish the shadow copy creation or deletion tasks before/after a snapshot is taken, corrupt shadow copies may be left behind on the client machine.
These corrupt shadow copies cannot be deleted by issuing the `vssadmin delete shadows /all` command. Instead, you receive the error:
Error: Snapshots were found, but they were outside of your allowed context. Try removing them with the backup application which created them.