I already found out that akeeba admintools WAF is caused the conflict. But I don't know how to solve Is this a VM2 problem or Akeeba or maybe the popup from the Gavick template? Also the Bikestore is in conflict with akeeba admintools WAF
I guess this option is available on professional Admin Tools version, and the one packed in storebox quickstart it is the free one! right? so in my case this is not the root cause!
Had a simular issue with StoreFront template (at www.longa-utrecht.nl). Template seem to load twice in 2 different formats and printed on screen. I needed to add cart and json to the Admintools WAF configuration: List of allowed tmpl= keywords: component,system,raw,cart,json