ICS-10064 error when calling a stored procedure with the ADW adapter

Content

I'm having trouble invoking a stored procedure using the ADW adapter in a scheduled orchestration.

My procedure is very simple:

create or replace PROCEDURE procedure_name (dummy_var IN NUMBER, dummy_var2 IN NUMBER) IS
BEGIN
update table1
    set 
        column1 = (select max(some_value) from table2);
END;

(The dummy variables are not used. same error is raised when not including them in the procedure.)

This leads to the error:

An error occurred while preparing mapper object. [Cause: Root Element is Invalid for the Target URI ''{0}''] ICS-10064 : An error occurred while preparing mapper object. Root Element is Invalid for the Target URI ''InputParameters''