Virtual Xen Server backup fails in Symantec Backup Exec 2014

Our Xen Server backup fails within backup exec with primary error: Completed status: Failed
Final error: 0xe00084af - The directory or file was not found, or could not be accessed.
Final error category: Job Errors

Backup- \\XEN\C:V-79-57344-41488 - Due to one or more errors in \\XEN\C:, this backup cannot be used for conversion to virtual machines, Simplified Disaster Recovery (SDR), or a complete online restore.

Directory Windows\Microsoft.NET\assembly\GAC_MSIL\Microsoft.Build.Framework\v4.0_4.0.0.0__b03f5f7f11d50a3a\ was not found, or could not be accessed.

None of the files or subdirectories contained within will be backed up.

I looked in the windows events on the Xen Server:
     Volume Shadow Copy Service error: Unexpected error calling routine IVssBackupComponents::SetContextInternal.  hr =                            0x800706ba,      The RPC server is unavailable.
.

Operation:
   Add a Volume to a Shadow Copy Set

Context:
   Execution Context: Requestor


I tried reinstalling the client and adding the server back to backup exec to no avail....