Time Machine: why doesn't it back up Applications?

[AlanWilson]

I have nothing excluded in Time Machine Preferences.

My backup external drive failed about a year ago: I replaced it and backups continued.

Had to restore an application recently: found the applications folder in Time Machine was empty, however far back I went.

Does Time Machine know that I replaced the backup drive? If not, perhaps /applications has not been backed up since nothing has changed since I replaced the drive - ? But I have been told that the backup information is stored on the backup drive, so Time Machine should know that the drive was replaced and do a full backup as the first one - ?

If that is the problem, how do I force Time Machine to do a full backup?

 

[Bruno09]

It is (was) a bug (I had it too).

To solve the problem you must delete the Time Machine plist file.

Path : Macintosh HD / Library / Preferences / com.apple.TimeMachine.plist

Turn Time Machine off (System Preferences / Time Machine), then move that file to the trash, then turn Time Machine on, choose the backup disk, and "Backup know".