vQuiz works perfectly with mootools, there seems some other issue on your site. As I stated in my Email, You are using some code optimisation plugin which is causing the issue. Please contact our Sales team via Contact us -> Request a Quote form, We'll look into it.
You need to enter your same Email ID & Password which was used to subscribe for vQuiz. Please note you need to enter Email ID not username. If you are doing the same and still having the issue, Please let us know, We'll look into it.
I have a problem with jQuery in the Vquiz component. Although i disabled the jQuery function within the Vquiz configuration it doesn't want to work.
The link for the quiz is: tankstationvoormensen.nl/tvm/index.php/tankwijzer