Diagnosis
The incidental expenses characteristic is not defined for theincidental expenses key in the specified tenancy law, i.e. you have notspecified whether operating or heating costs are involved.

System Response
The data for the incidental expenses participation will not be created.

Procedure
Check whether the incidental expenses key and the tenancy lawinformation has been defined in the incidental expenses keycharacteristics maintenance screen.
Another reason for the error could be an incorrectly defined tenancylaw for the rental agreement business entity.