iTunes Backup, 8 errors: Separator unmatched+Signature unmatched

[N8261D]

you saved it in a .rtf file. Which is a Rich Text Format file. That adds a bunch of unseen data.
You need to save it as a plain text file (.txt) which would be just the letters you typed (and not extra data such as font, color, style, etc)

See https://apple.stackexchange.com/question...plain-text how to do this for your TextEdit app.

Okay. I have done that. Now I am getting a token length exception error