Yeah it's a PHP error most likely. We upgraded to PHP 5.4.x a few days ago and that has made some outdated code stop working. You can take a look at the error_log in public_html to check out what's wrong exactly. I'm afraid I can't do much more. Fixing the code will be up to you.
Thanks for the donation by the way. We thought of axing the site a year or two ago when we did a big server clean-up but decided to keep it running as a favour to the community.Go to the full post