After the upgrade to version 2.8 of WordPress my visual editor, the TinyMCE editor used to edit most of my posts disappeared and did not want to start at all. I tried four different browsers with the same problem, Google Chrome, Mozilla Firefox, MS Internet Explorer and Opera and they all had the same problem.

I found other people on the web with similar problems with various solutions but nothing they did helped me so after some trial and error this is what I did and it worked for me:

1. Disabled all plugins.
2. Removed the site from ”Gears” in firefox browser.
3. Cleared the entire browsing history, cookies, and all user data from the browser except for saved passwords.
4. Logged in to the site and went to ”Tools->Upgrade” and did a re-install of the 2.8 version of wordpress.
5. Re-enabled the plugins I wanted.
6. The visual editor now works.

This solved the problem also in Google Chrome but required a restart of the web browser. The Gears is disabled in the ”under the hood” settings of Chrome.

I hope others may have some help from this because it was rather annoying. I think it was a problem with saved cookies in combination with the google gears.