My MacBook is currently using around 180GB of its internal drive. However, when I plug in my 250GB external drive to make backups of my Mac, I incessantly get the error "your backup drive does not have enough storage to perform the backup."
My backup drive still has 15GB free. From my understanding, older backups should be deleted to make space for newer ones. Is there any reason why Time Machine does not automatically delete the older backups to make space for the newer one?