Any kind of VMware Job, regardless of the VM or Target, would fail with "Process 'VMware Plugin' (PID 'xxxx') has crashed!" or just "Backup Failed". If it's the latter, a "Process 'VMware Plugin' (PID 'xxxx') has crashed!" may appear in the general logs around the same time the "Backup Failed".
Gathering a VDDK Log contains the following entries before a "Panic: Win32 invalid_parameter error":
[Originator@#### sub=cleanup] HotAddMgr::ProcessItems: Hot-removing disk [<datastore>] <vmname>/<name>.vmdk at SCSI #:#
If an SSH session is made to any of the hosts and a cat/less/cp or any command is issued to the *.vmx, *.log or any file for the VM on the error above. There would be an error saying the file is in use. Doing the same for another VM would work.
Workaround:
Try doing a vMotion to a different datastore to help release the software lock.
After this all the VMware Backups should run, even after moving back the VM to its original datastore.
