So having updated to macOS Sierra, I get 'Preparing Back Up' continuously when trying to back up to Time Capsule. Any advise? Thanks MBP, early 2011 --- Post Merged, Sep 20, 2016 --- Have tried this but without success "It is because your Mac still thinks it is backing up to a disk on an old router. Simply fire up System Preferences from --> System Preferences --> Time Machine --> Select Disk. Select your disk and the backups will begin again."