Time Machine Backup Error
I am the proud owner of a new iMac 24 Desktop running Ventura 13.2.1. I re-formatted my old WD Passport for Mac and set it up to use as the Time Machine Backup. It will not complete the backup. Initially I get the error "/Library/Application Support/ApplePushService/aps.db-shm". Thereafter it says that the backup disc is not available. I've tried first aid and 'remounting' with no joy. Is the problem that I'm using an old 'WD Passport"? If not what should I do? Please keep it simple as I'm a bit of a dinosoar. Thank you for any responses.
iMac 24″