I have just upgraded to 2.2.1, though I do not think it is related.
Whenever I try to edit any theme (all of the many many that I have), I get "Sorry, that file cannot be edited." I have tried changing permissions, reuploading the theme, reuploading the theme-editor.php, I even upgraded PHP on my account to 5, with no success. This seemed to have happened out of the blue, I was editing fine Sunday, and now on Monday it is giving me this error. Is there debug/logging I can turn on to see whats going on or does someone know what is going on under the hood so I can troubleshoot this?
The only other symptom, and it seems related, is that the Plugin editor is also not functioning properly. It is "stuck" on editing "wpg2/wpg2.php" which is my WP gallery2 plugin. No matter what plugin I pick to edit, it is always editing that one. It allows me to edit it, and seems to save alright, but again I can not pick another plugin to edit.