WiX CustomActionData is empty in called CustomAction

Question

once again I\'m stuck at a problem, that is probably easy to solve.
I want to extend a setup, created with WiX, to make changes in the configuration file of the installed pr

Answer 1

The Property attribute value of DemoDatum.SetProperty should be equal to the Id attribute value of the deferred action. So, either change the property name to DemoDatum, or change the Id of the deferred action to DatumEintragen.