We’ve discovered an issue involving TinyMCE and Firefox 11 that causes the TinyMCE to stop working when you have more than one text field on a page. This problem appears in a number of places, including assignment view. The work around is to use a different web browser. The fix is to install an updated version of TinyMCE in Moodle. This 1.9.16+LAE v1.6.1 Alpha 1 release does this, baking in LAE_19_TinyMCE35b2 into the LAE v1.6 release.
This code has been tested, but be aware it is alpha code and should be thoroughly tested before being deployed on your own systems.
Getting the release: