Certain web pages not loading properly

Hello, Kioskea. I've been a fan of the website for a few weeks, but only recently decided to ask a question, as this problem has been annoying me for quite a while.

Recently I switched my browser from Firefox to the Nightly 64 bit build. I had no personal reasons to do it, Firefox was working fine for me and I've never had any problems with web pages. After I switched to Nightly, the pages from the Wikia family (not Wikipedia, but the wikis - Lego wiki, LoL wiki etc.) started loading really badly - font is all times new roman, all text is on the right side of the page and it looks just like it loaded 40% through. I cannot confirm if this is due to Nightly switch because the problem persists even if I open the pages in Firefox. I've tried clearing cache, ctrl + shift + R refreshing and opening them in incognito windows. None worked.

I'll also attach a picture of the page. Again, only the wiki family pages load badly as far as I know. Other websites I regularly visit load just fine.