Time Machine Error 19

Please review If you can't back up or restore your Mac using Time Machine - Apple Support.

Unfortunately, Error 19 can mean that there is a corruption problem with your backups using a Time Capsule. So, before we go off on a wild goose chase, we need to confirm that you are in fact backing up your Mac to a Time Capsule.

Is that the case?

Please be advised the Erase your backup disk instructions in the Apple Support document I referenced apply only to backup disks directly connected to your Mac. If in fact you are using a Time Capsule, then the following applies: Erase an AirPort Time Capsule in AirPort Utility on Mac - Apple Support.

Sorry, but this cannot be correct. Time Machine is not a device. Time Machine is a software application on your Mac that is used to back up the data on your Mac to another hard drive.

That other hard drive might be a Time Capsule. A Time Capsule looks like this:

Or, an older model of the Time Capsule looks like this:

Do you have a Time Capsule......or......do you have a USB hard drive that is connected to your Mac?

Thanks, but we still don't know if you are trying to back up to a Time Capsule...or...to another hard drive.

It sounds like you are confusing Time Machine......(which is software on your Mac)......with a Time Capsule......(which is hardware).....an Apple router with a built in hard drive that is used to store backups of your Mac.