If TinyMCE is not loading properly or the editor is stuck in HTML mode and won't switch to Visual, there are several things to try and fix it:
1. Make sure the "Use the visual editor" checkbox in your profile is selected.
2. Clear your browser's cache, quit it, start it again, go back to the write page and force-reload it several times, while holding down Shift (Firefox) or Ctrl (IE).
3. Delete both
wp-includes directories and upload fresh copies from the WordPress installation package.
4. In Firefox, go to the following URL:
var tinyMCEPreInit = ... and last line starting with
If it's a text file but doesn't start and end as above, it is being pulled from network cache somewhere between the computer and the server. Reloading it a few times while holding down Shift/Ctrl may force the cache to refresh. After this, go back to the write/edit page and refresh it again.
If it's full with garbled characters, it usually means that compression on the server is enabled, but not set properly in php.ini. In this case either edit tiny_mce_config.php and change
'compress' => true,to
'compress' => false,to stop the compression of TinyMCE, or download this small plugin that will do it automatically.
If TinyMCE loads properly but the "Add Link" or "Edit Image" pop-up doesn't work or show only empty frame, right-click in it and select Refresh while holding down Ctrl in IE, or This Frame -> Reload while holding down Shift in Firefox.
This is the same caching issue as above, but affecting only the pop-ups. Try these URLs with Firefox:
and force-refresh them several times to try to update the network cache.
In any case, the pop-ups will start working after a few hours (or may be a day) when the cache is refreshed.
And finally if none of the above fixes worked, try Firefox with Firebug and notice any js errors or any missing files (red 404s in the "Net" tab). If there are js errors, copy only the first one and see if it already has been discussed here, or open new thread with the specific error.