Just a quick note for me and anyone else with a similar problem:
If the rich-text editor on a WordPress blog is not displayed correctly (i.e. no visible toolbar or no access to writing area — I recently had both symptoms) then the problem might be an incompatible library used in a plugin.
For my case, the solution of the problem was to deactivate the “Spelling & grammar” box of the JetPack plugin by selecting “Learn more” at first and then “De-activate”.
Visit The Light of the LAMP blog for more…