AppEngine with Restlet handling requests, NullPointEerexception with DomRepresentation response

Question

After deploying my App Engine app and doing a POST request that is supposed to return XML, I get the following error:

org.restlet.engine.http.HttpServerAdapter commit: An exception occured writing the response entity
java.io.IOException: Couldn't write the XML representation: java.lang.NullPointerException
    at org.restlet.ext.xml.DomRepresentation.write(DomRepresentation.java:275)
    at org.restlet.engine.http.HttpServerCall.writeResponseBody(HttpServerCall.java:510)

Doing the exact same request on the app ran locally does not cause any errors.

Answer 1

Maybe you have data in your local db, that is not accessible in the deployed version? Please give some more background information (code, libraries), if that is not it.