Hi Ingo,
thanks a lot! I’ve tried the example as well and it worked.
The variable expected from the TaskDecorator should be a format like this [demo, f574398] to get it work.
The differences to my own project was that the folder src\main\resources\META-INF\services with the file org.camunda.feel.valuemapper.CustomValueMapper was missing.
Everything is working now!
Have a good day!
Michael