Firefox opens some sites with text only

[wappe]

So for example when opening website LoL Pro - Pro League Of Legends Guides and Videos it looks like this

I have had the same problem with some other sites. Sometimes it looks like that, sometimes it works correctly. I dont know if this has anything to do with this, but i runned some kind of computer cleaning program and after that the website started looking like that. But I had the same problem with an other website named solomid.net, but now it works normally.

EDIT: Ok when I opened website www.owned.tv it says

Error: the xajax Javascript component could not be included. Perhaps the URL is incorrect?
URL: /inc/xajax/xajax_js/xajax_core.js

 

[mart44]

Firefox may have got switched to 'No Style' in the 'Page Style' options.

Turn on the Menu Bar and go to 'View'. Go to 'Page Style' and make sure that 'Basic Page Style' is selected.