The backup disk image ".sparsebundle” could not be accessed (error -1).

The backup disk image “/Volumes/Data/My Computer.sparsebundle” could not be accessed (error -1).

This message appeared after normal operations with the Time Capsule for over a year. I wanted to update to the newest OS X but not before backing up my system. I cannot find a single post that has helped online.

I also don't know how to access my Time Capsule data to delete the sparsebundle file.

Any suggestions?