Bizarre error on the website.... (found the cause)

ShelLuser

So I saw a really nice thread on the forums and I'm trying to respond. Only to be met with the error in my attached screenshot.

Now.. my post was relatively long, but even when I tried to split it up I still got met with the error, only when I added a one liner things worked?

Does anyone have a clue what is going on here?  If my post is too long then surely the forum should be able to tell me?

(edit)

Solved!

As it turns out the forum does not appreciate emoticons. In Windows 10 you can simply pull 'm up using "win + ." and yah... it seems that's where things go sour here. Even so.. still an odd error message IMO, I hope this can help.