A fatal error occurred during a Windows Server Backup snap-in (Wbadmin.msc) operation.
Error details: The server threw an exception.
Close Wbadmin.msc and then restart it.
For server 2012, 2012 r2, and 2016
- Remove/backup the log files: C:\Windows\Logs\WindowsServerBackup
- Uninstall the feature: “windows backup server”
- Restart the Server
- Restart again for good measure
- Install the feature: “windows backup server”
- Open Cmd (with admin rights) run (and answer yes): wbadmin delete catalog
- Start the Backup Service
- Recreate the backup Job and Services (as needed)
That should do it.