so that service is running locally on your machine?
Do you have administrator privileges on your computer? (I'm not sure whether they are necessary for this, but it's a possibility)
Have you entered yourself (your logon credentials) as the user the service is using? Did you have to change your password recently (in that case, you'd have to change it for the "service_user", too)? (We settled for using a fictitious user whose password does not expire; usually our passwords expire after 30d due to policy)
It could be two different issues. First at all, make sure your user is into the Qlikview Administrator Group. If that's not the issue, maybe your license is not updated.
