mybb not showing full post text 1.6

[mr_x]

Hi guys nice site you have here pleased I found it

I have a problem with mybb and cant find how to fix it anywhere.
here is what happens when someone makes a post in any section or reply to a post some of the text is missing.

when I click full or quick edit I can se the full text. I have no Idea what's wrong with it I have changed theme and it still does it have any of you guys any idea what could be wrong please

Thank you inadvance

[RateU]

What kind of the missing?
It is replaced by other text or what?
Maybe you need to check whether you have a plugin or core file edit that cut the post message.