Every time I tried to create a thread in these forums, it errors out complaining of invalid HTML was found in the body of the message.

I'm just using the existing "Body" editor, without any settings even.

(Correct the highlighted errors and try again: Your post has been changed because invalid HTML was found in the message body. The invalid HTML has been removed. Please review the message and submit the message when you are satisfied.)

How does this error out every time? Doesn't anyone test these things?

Using on Firefox / MacOS

Edit: it seems to not like blank lines in the body. Oh god.