Topics are broken?

First topic message reminder :

Technical Details

Forum version : #ModernBB
Position : Administrator
Concerned browser(s) : Mozilla Firefox, Google Chrome, Internet Explorer, Opera, Safari
Screenshot of problem : https://i.imgur.com/9cFjNqD.jpg
Who the problem concerns : All members
When the problem appeared : Since the beginning
Forum link : http://fallenskies.actieforum.com

Description of problem

Hello,

Me and my friends recently made a forum. Since ModernBB was new we used that to make our forum. But we've run into some troubles with it. Two of our topics are 'broken', if we post in it the entire topic breaks and we can see nothing but the last message. This is in two topics that I will link below. I'll also attach a screenshot of what happens.
Can this be solved? Users can't enjoy the forum right now because they want to post in that topic but they can't.

Topic 1: http://fallenskies.actieforum.com/t8-faceclaims
Topic 2: http://fallenskies.actieforum.com/t82-a-sky-full-of-stars-open#644

EDIT: one more broke: http://fallenskies.actieforum.com/t106-gz-ts-my-responsibility
It's getting worse..
EDIT2: And another one... http://fallenskies.actieforum.com/t101-watch-me-steady-open

Bumping this thread so it's not locked.

Tech team have been asked to look in to this and is now marked as in progress

Hello @Kiekie, sorry it has took so long for us t get back to you on this matter but out team had to make sure things was ok before making their report back to me.

This it the reply i have got back from them.

head office. wrote:16-10-2017 10:08
Hello APE, the technicians don't reproduce the problem and cannot say what it is
If the administrator is using adds , maybe check if the problem doesn't come from there....

My next plan is the following.
Can you turn off all javascript's and css files and any ad's you have on your forum and then test the page you gave me to see if the problem goes away if yes then turn one by one on again until it shows it's face again.

Just to give you an update and to keep this thread open.

@Kiekie we have not forgotten you we are still working on the problem and we hope to have some more news on this matter soon as it comes in.

kind regards

APE and the team.

Hello @Kiekie

We have got news back from our head office about your problem and this is what we have found.

Hello,
if you deactivate the HTML in messages ( ACP - General Tab - Messages & Email - Configuration - Allow HTML) the problem doesn't appear. So there is a problem somewhere with HTML codes (maybe in one of the messages above)

This maybe in some ones signature or something they have added to there posts (copy and pasting from some other site can do this if not coded the same as our site.)