On the remote computer running the plan, open a command prompt. Type 'vssadmin list providers'. If any other provider than Microsoft Provider is listed, enter microsoft in to the VSS provider field in advanced settings of the plan.
Check the status of VSS writers. At the command prompt, type 'vssadmin list writers'. Check to make sure SQL and Exchange writers are present and in a stable state, if running SQL or Exchange plans. If SQL writer is not listed, make sure the SQL Writer service is started and set to automatic startup type in the services console.
If writers are in a failed state, restart the computer. SQL Writer service may be restarted without a reboot.
Make sure the drive that is configured to hold the snapshot change directory has adequate free disk space. Open My Computer, right click the C: drive, select Properties, and select the Shadow Copies tab to view configuration settings. In some cases, moving the drive that holds the snapshot clears up errors reading a snapshot.