The changes you made in response to my other thread, about "Likes" and the confirmation page, appear to have resolved this issue, too.  The text editor box is now enabled.

Were those settings you updated always set to the values they had before you changed them?  I ask, because I'm still suspicious that nothing here in the forum changed, but rather that accumulating changes in the browser resulted in a conflict.  I'm fairly certain that when the forum was resurrected, the text editor was enabled for me in the Firefox release I had at that time.  If our settings have been the same since the beginning, it makes me think browser updates are the culprit.