I have the same issue with a new install of 3.4.1. The admin editor screen hgas the text as white and the background is white. SO the only way to see what you type is to hightlihghti it. I’ve gone into a completely new “juser” in Windows 7. new IE and new chrome browsers. Shut off every add-in in IE. Reinstlled the WP-admin and wp-inlcude file and still not fixed.
Also, whenthe text us hiughlighted I always see the html. Clicking the HTML tab does nothing. Clicking the Visual tab does nothing.
Clciking the help at the top right does nothing and a few other buttons doen’t do anythinmg either.
The text I oput into the editor shows on the site, justnot in the editor. https://www.DrBackYard.com/blog ids my new blog I’m trying ti use.
Can you help?