I like to google error messages that I encounter, as any good developer should. I googled the message “… has an invalid qualified name.”, and I got what has to be one of the most helpful reference messages ever:

XML-21017: invalid qualified name: string
Cause: The qualified name passed to a DOM function was invalid.
Action: Fix the qualified name.

Wow. Thanks. I need to fix the qualified name now do I? Thats really helpful. You really are a helpful reference aren’t you?