Search function has stopped working

We’ve been having problems with our website for the past couple of days. In an attempt to resolve the main issue we updated WordPress and all plugins. However I just noticed that the search function on my site has stopped working. Where before the user would have found listings matching the search terms now there is a blank page. Any idea why this might be happening? Any advice on how I can resolve this?

Thank you
Gran Alacant Properties
http://www.granalacantproperties.com