TM back up occasionally fails

Question

Every so often TM reports that 'back up failed'. If I then manually enter TM to back up it's fine. Any ideas as to why this happens?
Thx

Answer 1

There is a rile in that folder named com.apple.timemachine.supported that is reported as an empty file. If you did not see it listed, then it may be invisible. You can make invisible files visible by doing the following:
Enable Finder to Show Invisible Files and Folders
Open the Terminal application in your Utilities folder. At the prompt enter or paste the following command line then press RETURN.
defaults write com.apple.finder AppleShowAllFiles TRUE
To turn off the display of invisible files and folders enter or paste the following command line and press RETURN.
defaults write com.apple.finder AppleShowAllFiles FALSE
Alternatively you can use one of the numerous third-party utilities such as TinkerTool or ShowHideInvisibleFiles - VersionTracker or MacUpdate.
Once you have toggled the Finder to show invisible files look in the folder for the above file. Drag it to the Trash. Turn off the display of invisible files.
Now start a TM backup. See if this fixes the problem.