I'm using Quercus/PHP on AppEngine. When I run a simple script with file_get_contents($url); I get an error: java.lang.NoClassDefFoundError: java.net.Socket is a restricted class. Please see the Google App Engine developer's guide for more details. I've googled and although I find that other's have run into the same error, but the cause seems the vary. What do you think is cousing this error for me? I'm using the latest AppEngine Java SDK, and the latest Quercus.