I get a notice popping up but cannot find out what is throwing this to me. The notice says (translated): "This action can not be performed because this field can not be changed."
The situation: I display several fields from a relationship in a layout (not fields fro the actual main record but additional information fom a related record). One of this related fields is a drop-down menu. And if I change the value in this drop-down menu the notice pops up. If I cllick "OK" tha changed is performed and shown as the actual entry in the pop-up menu.
Any hints to look for?