VSS Error E_UNEXPECTED (0x8000ffff) - Backup for Files

Written By Tami Sutcliffe (Super Administrator)

Updated at July 28th, 2021


Open file backup fails to initialize because of the error E_UNEXPECTED (0x8000ffff).

This can be caused by many of the internal Microsoft components that are part of your operating system. This is Microsoft's generic error message to say that something went wrong, but the details of the error are only contained in the Windows Event Log.


This error can be caused by the Volume Shadow Copy windows service having the startup type set to Disabled. To resolve this error, follow these steps:

  1. Start the Services task within Administrative Tasks. Alternatively, do: Start. Run. services.msc
  2. Locate the Volume Shadow Copy service in the list.
  3. Right click on the service and choose Properties.
  4. Change the Startup Type to Manual.
  5. Click OK to apply your changes.

This error also has many other causes. You should use the Windows Event Viewer to look in your system log for VSS or Volsnap errors and see what the error messages say. A search engine can often help you find a Microsoft hotfix or KB article with some resolution. You can also save your Windows event log and send it to technical support.

A list of known Microsoft KB articles and hotfixes are available at: