https://imgur.com/kbj2sGl
This happened when I tried to post in my Mafia thread. it kept saying it after I've deleted parts of what I was trying to post. I know you can post more then 85 chars per post, because of huge posts made in the suggestions boards.
Same problem for me

i wonder if it is just that thread? I can add more to previous posts, but no other posting is possible on it.
Weird.... Don't happens to me.
it might just be that thread. which sucks.
I'll try if i can post in that thread...
Thenn i delete post
EDIT* - Nope, can't post in that thread, its just the thread i think.
the error there clearly staten in english
when you reply it adds reply to the thread so it becomes too big
Elaborating on what CeFurkan said, it's not the post itself that's too long; it's the TITLE of the post. It is, in fact, the thread's fault. The title is so long that the "Re:" makes it too long to post your reply. Delete the "Re:" added on in the beginning and you should be fine! It's happened to me, and this has always worked. Hope this helps.

Oh yeah... this error XD The title was way too long; it can'be over 85 Characters

in other words, D1 was fine and D2 isn't. ohtay.
What makes an snow fall off a tree branch? that last little snowflake...that was just 1 snowflake 2 many...
Anyways in your case it happened to be the number 0...on 3/10 that was the 1 character too many...
locking this because you know what was wrong...and are now able to post in the thread again