PowerProtect: Virtual Machine backups are failing with error ABV0006 "unable to download config file"

ABV0006: VM Direct engine 'localhost' is unable to back up the virtual machine 'MY-VMNAME' on vCenter 'MY-VCENTER'.

Protection of this virtual machine by the VM Direct engine cannot be completed because the backup was unsuccessful.

Review the error details and summary log in the Jobs window, or review the log files at /var/log/brs/vmdm for more detailed information to troubleshoot the issue.

YYYY-MM-DD HH:MM:SS INFO * -  Session complete with failure BackupJobSession(state=Failure, id=7cfa28c2-0abe-4e1a-b3e9-a6afa1069ac7, clean, error: code=500, text=Backup has FAILED.  Unable to initialize Backup Descriptor.  HTTP Get request unable to download config file '[MY-DATASTORE] a2968c64-2a10-5ea8-df31-e4434bbad83c/MY-VMNAME.vmx' using URL 'https://MY-VCENTER.MY-DOMAIN.COM/folder/a2968c64-2a10-5ea8-df31-e4434bbad83c/MY-VMNAME.vmx?dcPath=MY-DATACENTER&dsName=MY-DATASTORE'. HTTP Status code: 404., target=MY-VMNAME)
YYYY-MM-DD HH:MM:SS ERROR * -  VM Proxy BackupJobSession failed -- Backup has FAILED.  Unable to initialize Backup Descriptor.  HTTP Get request unable to download config file '[MY-DATASTORE] a2968c64-2a10-5ea8-df31-e4434bbad83c/MY-VMNAME.vmx' using URL 'https://MY-VCENTER.MY-DOMAIN.COM/folder/a2968c64-2a10-5ea8-df31-e4434bbad83c/MY-VMNAME.vmx?dcPath=MY-DATACENTER&dsName=MY-DATASTORE'. HTTP Status code: 404.