20000 character limit on posts

Not sure if this is a bug or a new limitation but I am updating the Ryu matchup thread and was trying to move all the info from one post to a reserved slot with copy and paste.It tells me to enter a post with no more than 20000 characters but it has already been posted so I don’t understand why it would say that when all I am doing is copy and pasting without adding anything.What should I do about it?

That’s most likely because the post you’re trying to copy from was made before the switch to Xenforo.

Okay so it is a new limitation,thought that might be it.Thanks