Backups of some Linux VMs are are failing at the point of File-Level Indexing on a backup
(CentOS 5.11 x86_64 is one such VM with the issue)
The VMware Plugin crashes when it tries to process the sparsed 'lastlog' file on the File System of the VM.
This is found to be a known issue with sparse file-level indexing on Linux EXT File Systems.
NOTE: A quick investigation of the VM showed a user account (nobody) with a UID of 65535 which triggered the sparse file.