Re: [appengine-java] Not allowed to access system class loader.

Is this preventing your task from running? This is generally a harmless exception. Here's another thread on the subject, though your stack trace is a bit different:

[appengine-java] Not allowed to access system class loader.

A simple servlet which reads some data from a table - and query analytics service and store data in another table. When i run this servlet from browser it works (always). I have scheduled this servlet to run as cron job and it is not working at all. And i see the below exception in App engine