I suddenly began experiencing this problem yesterday. I can edit all pages EXCEPT sidebar.php (I could earlier). When I try to edit, I receive the error:
"You don't have permission to access /wpblog/bobg/wp-admin/theme-editor.php on this server.
"Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request."
I can edit the file through CPanel.
I queried my host. Here is the response:
"We have mod_security configured for the server. This is used for security purpose. On submitting your file, it contains certain pattern,in post payload. This is what causing trouble. You need to contact your programmer and remove the patterns like ":space:"."
Anybody have any ideas?