I got this on my forum

It happens when I check an extension to install or trying to check for updates, so it's supposed to be an ajax issue.
Can anybody advice on it?
In few words when i'm checking an extension to install browser displays its window text like this:
<*meta http-equiv="content-type" content="text/html"; charset=utf-8"> [extension's name]
0 · ·
Comments
- Spam
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0 · Insightful Awesome LOL ·- Spam
- Abuse
0 · Insightful Awesome LOL ·- Spam
- Abuse
0 · Insightful Awesome LOL ·- Spam
- Abuse
0 · Insightful Awesome LOL ·