I’m getting this error in Firefox:
Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at http://www.amchimneys.co.uk/wp-content/plugins/lightweight-social-icons/fonts/fontello.ttf?13736647. (Reason: CORS header ‘Access-Control-Allow-Origin’ missing).
Can you check that both of your URLs set in “Settings > General” are the exact same? (Both have or don’t have www. etc..).
Then make sure the URL you’re visiting the site with is the same as those URLs.