Hello.
By doing a differential Backup based on the archiv flag, BE is doing a backup of the whole directory structure, even when in the directories are no modified files to backup. Means the archiv flag of those files are not checked.
I looked on the archiv flags of the files in the directories, they are not checked, I looked on the archiv flag of the directories itselves, the are not checked. but nevertheless BE shows in the Restore dialog by selecting the files to restore only empty directories.
I am doing the backup thru