Keeps Disconnecting.

[MMM]

Recently updated to the newest version of SuperDuper and also macOS Sierra.

Now if I try to do a backup the hard drive disconnects after around a half hour...

What could cause this? How should I trouble shoot? It was working fine before the update.

[dnanian]

Drives "disconnect" when they stop talking to the OS. After a certain amount of unresponsiveness, the OS considers them "ejected" (they often unmount immediately). It has nothing to do with SD! except, of course, we're asking the OS to write to the drive.

So, what you need to do is simplify, check cables, etc.