It's not working because you exceeded the allowed BE installations per user ... the editor menu auto turns off if you install BE more than once. J/K of course :)
It sounds like the entire tinyMCE WYSIWYG is not loading at all ... and you're just seeing a plain textarea.
textarea into a WYSIWYG editor.
What happens if you check and then uncheck the 'raw HTML editor' option?
I've not seen this before ... so just taking some guesses.