Published a post a couple of days back, and everything was fine. But today suddenly found that I could not add tags to a new post or when editing a post. Then I noticed that the short codes across the top of the post content field were missing. Could not switch between the visual and text editors. Could not pull down Screen Options or Help.
Problem with Administration Panel > Posts, as follows: --
Screen options and Help non-responsive.
Cannot switch between visual and text editors.
Short codes (text mode) have disappeared.
Tags not working.
Attempts to fix | Result
Disabled plugins. | No difference.
Repaired database tables and optimized db. | No difference.
Switched to stock theme TwentyFourteen. | No difference.
Tested other panels, all seem to be in order. This problem occurs within the Posts panel. Edit: Also within Pages. Same problem.