I encountered a very odd issue today. After installing TYPO3 6.2 it seems that in the backend the htmlArea RTE is not enabled by default. I don’t remember that I ever had to enable this manually. Usually this worked. However in this case it doesn’t work and I’ve been told that this is a bug in TYPO3 6.2 which will be corrected. However I’ve later installed 6.2.1 and this issue is still there. But don’t panic, there is a solution for this problem.
Go to the menu item “User settings” on the left menu bar and then go to the tab “Edit & Advanced functions”. There you will find the checkbox “Enable Rich Text Editor (if available)”. Check it and you’re done, htmlArea RTE should work in the backend.