Differential or incremental backups fail if more than one virtual machine (VM) is in a selection list.
A Full backup was run on this VM, since the option to fall back to a full backup was selected. Incremental\\Differential backup methods are not supported for this VM.
A hotfix is now available for this issue in the current version(s) of the product(s) mentioned at the end of this article. Refer to the Hotfix link under Related Documents at the end of this article to obtain the hotfix needed to resolve the issue.