The file “Untitled.rtf” couldn’t be opened. – TextEdit
If you encounter this error, you’ll find various other solutions on the web…
But the solution that worked for me was simple:
1. Open System Preferences (click the Apple icon at the top left, then choose System Preferences…)
2. Choose Internet Accounts.
3.  Choose iCloud on the left, then scroll down to Documents & Data. Uncheck it!
Fixed.
I did everything but there is no Documents & Data box.
Hi Nathan,
try renaming your file as such : NAME.RTFD
adding the “D” should do the trick
Hi Nathan,
try renaming your file as such : NAME.RTFD
adding the “D†should do the trick !
didn’t work on OS X Yosemite –> even unchecking “textedit” from the “Internet Accounts/iCloud/Options” system preference
found a solution myself :-) –> add a “d” to signifie it’s a rich text document with possible attachments (eg images, animations).
Thanks! Textedit stopped being able to save any type file – unchecking iCloud seems to work. (El Capitan 10.11.6)