Creating a thread requires me to click the Post button twice. The first time I click it, I get a message saying "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." I didn't insert any HTML into the message, and I'm unable to find out what is causing the error. The second time I click it, it works.
Is there any way to view the HTML (source) of a post, to see what is causing the error?