Thank you Jeff. I followed your steps, and indeed, it was unchecked. Annoying thing though is that I can check it, but that it reloads, doesn’t show the custom filed meta box, and when I check in the preferences again, the custom fields is unchecked again?? I update the advanced custum fields plugin, but that didn’t solve it. I know, this doesn’t seem to be a bug in your plugin but elswhere, but if you have any thoughts…
Does the paid version works in the same way? (I think we will swich anyway), but I need to get this solved first.