Try deactivating all plugins and check to see if this resolves the problem. If it does, re-activate the plugins one by one until you find the problematic plugin(s).
Also see:
http://wordpress.org/support/topic/279132
It’s a crude workaround, but I’ve found I can make the visual editor come back by clicking on the HTML tab, saving from there, then returning to the Visual Editor.
It’s not a good idea to switch from the Visual Editor to the HTML tab and back again. It can seriously mess up your content. Pick one tab and stick to it.
Actually, you are lucky you can even do that. In my version of this problem the tabs are broken.
Are you using IE 7 or IE 8? Have you tried this under FireFox? In my case it works in FireFox but not IE 7 or 8.
I found deleting the temporary files from the browser history allowed a single edit – post attempt.
I get the same thing everytime i try to install a new plugin. The HTML visual editor and whatever functions are below the post section. Any suggestions
Same here. Plus My screen options don’t work, my permalinks don’t work and I can’t drag widgets
my debugger reports ‘tinyMCE’ is undefined
People – please stop tacking these onto pre-existing topics! They are very different problems that will, almost certainly, have very different solutions. If you have started a topic relating to your problem, please stick to it.
