An Error Occured While Executing Doinbackground()

I am using a doInBackground() method to save my database as a xml file and back up the database. it backs up the database and saves it but force closes when trying to save into xml

Solution 1:

Clearly something is null and you should figure out what/why. It's one of these:

WWActivity.this.application
WWActivity.this.application.getDataHelper()