Been a long time. Lots of other stuff to do. Now again some time to try and make this work. Hope you too can find some time to take a look at it.
I’ve added screenshots. Again of the code inside the Preview-field. Changed it according your advice. Sadly Chrome gives no errors in the console and the original error about the missing spjs_ListItemPreviewConfig remains.
Tnx for the quick reply. I adjusted the code in the description and changed the configdescription from 2 to 1. However the error remains the same, does that make sense?