Thanks Susan, it was only half, figured out one of the issues, there s two tv s used, one for the MIGx grid and one for inserting the image. The latter one was not assigned to a group.
It s now letting me choose an image, however the path is wrong so no image showing. In media source i assigned
as both path base url and base path, there s some folders in there, one is
.In the source of the page images are rendered as copied here:
<img src="slider/wijnkaart/wijnkaart.png" alt="Onze Wijnkaart" />
. Not sure why assets/images is missing?