I am helping a blind guy who runs mirror backups and has accidentally deleted some of the files backed up on the destination drive. Running the backup again adds only newly-modified files from the C disk.
I found a 3-year-old post which did not offer much consolation, but am wondering if there has been any more recent change which might make it easier to force the backup to start again from scratch (or better still to replace only the deleted destination files).
Since he is blind, it is hard to ask him to do what I did in this instance: delete all destination files, copy the old backup task, delete it and rename the "Copy of" version to the original name, then run it again.
Could you let me know if there is an option in the (accessible) menus which will do what he needs simply - it looks from the old post that he has to set "Clear backup" in the Advanced properties, do one run, then remove "Clear backup" to restore the Mirror "changes only" function which suits him best.