BackupExec error code E0008488

Hello support peers!

I am running BackupExec 2010 on a Windows 2008 R2 server (physical) that has reported this error when backing up several servers in one job:
V-79-57344-33928 - Unable to complete the operation for the selected resource using the specified options for the following reason: VFF Open Failure. This can be caused by low memory or disk resources.
Does anyone know if this message relates to low resources on the backup server or on the server being backed up? I have checked both servers and resources appear to be OK. I have searched google but this may be one of those generic errors that is logged for more than one type of error.

Thanks in advance for any replies!