There's a breakage in the links at the top of the page in freeexampapers.com (below the news, after 'You are here:')
If you go three levels or more deep (e.g. GCE A level > Maths > AQA), and then click to get back to anywhere apart from the first level (in this example, click the 'AQA' link (which should just refresh the page) or the 'Maths' link and it'll navigate to a 'blank' page with all the FEP theme, but no listings.
My suspicion (based on the 'You are here:') notice on the 'blank' page is that is joins together all the words of categories (e.g. A LevelMathsAQA) and tries to go there, but it doesn't exist.