After installation server is recognized as a "private server"?

[mikettl]

Hey guys,

I installed the Questhelper addon just a couple of minutes ago. Now after the login I get 2 error message: 1. Questhelper is broken, you may restart WoW. 2. Questhelper does not work with private server.

Especially the 2nd messages confuses me, because I never played on a private server at all. Since at least 3 years I play on US server Garona.

Is there something I didn't realize?

Many thanks for any hint :-)

Best regards
Mike