Not a bug Error posting threads and replying to threads (Also shoutbox!)

Just about 20 minutes ago my forums messed up, I've changed no files or templates before to cause it to do this.

Whenever anyone tries to post a thread it gives them this error:
" Please enter a valid message. "

Also whenever someone tries to post a shout in the TaigaChat shoutbox the shouts don't even load, nor be entered.

And the quick reply box is gone. the text box doesn't show up and says the same error as above "Please enter a valid message."

I've checked my templates, but everything is there and I've tested another template too. I don't know what's wrong really.