XF 1.5 Is there a limit to how many characters in a post?

I have a poster trying to post content on my forum, and he's said it tells him it's too long. That seems odd, but is there a way to change it?

 

I have posted many guides on various XenForo forums, and the default amount seems to be 30,000? I am not positive though.

 

I hate it when the answer is obvious. Thank you. I still fumble around the ACP like a newb.