Diagnosis
The workflow has no steps that can be made ad hoc.
Only steps to whichresponsible agents can beassigned (such as activities or user decisions) can be made ad hoc. Noresponsible agents can be assigned to the step for this.
Steps that already have reponsible agents are not made ad hoc.

Procedure
Delete the agents that are already entered in the step definitions thatare to be made ad hoc, and execute the function again.