I kept getting "enter a valid message" every time I tried to make a post or start a thread. I had to turn-off the rich text editor option.
Hmmm. I can't seem to reproduce it on this end. I'm curious to know if you still have that problem using a different browser.
I'm using the latest edition of Chrome 64 bit. Has been rock solid. After I logged-off ET, all was well for a short period of time. Now I get "unspecified error" when I post now.