OK, I have no idea what just happened. One minute, the tinyMCE is working fine, next minute it is completely gone.
This is what I was doing when the problem occurred:
Copied my site to a different folder with a different name.
Copied my database tables to another database.
Edited the header.inc.php in that new folder to correspond to that folder and the new database.
When going through the new site in the new folder, I noticed that I did not get the top section of the tinyMCE block, it just says paragraph or format or nothing at all. So, I went to the original site to see if the TinyMce is working there, and it does not anymore. The last changes to the site were 4 days ago, and the tinyMCE worked fine then.