I am using El Capitan 10.11.3 Previously the MyBook 2TB was working fine but now will not back up in TimeMachine and is read only. I have gone to Get Info and tried to change the permissions but despite unlocking it, I cannot change to read and write. What can be done without having to reformat the external drive. It was working and then suddenly it wasn’t.
Hello, you can go into disk management and run a first aid and make sure that the “Fix Permission” toggle is on.
You cannot do that if the IMac does not recognize the drive. Since installation of ElCapitan, the IMac does not recognize that the MyBook drive is attached via USB.