Windows error 0x80070002 Cannot find file specified - HELP!

Hello! When running all but one of my created backups, I get the following error:

Windows specific error (0x80070002) The system cannot find the file specified.
Error source: (this is blank)
Error Code: 0x80070002

You may find more details on this problem... Knowledge Base.

The only backup that runs without this error is one I created today to test this issue. It backs up a single file and I tried it backing up a file from each of my drives.

I searched this forum and the Knowledge Base to no avail.
I've attached a screenshot.

Does anyone have a fix?
Thank you!!
Lisa W.
Attachment 886