Diagnosis
You have tried to create a substitute relationship for a period thatoccurs entirely in the past. This substitute relationship would nothave any affect on the system because substitutions in workflow arealways evaluated for the system date.

System Response
The system will not let you create this substitute relationship.

Procedure
You should create a substitute relationship for a period starting fromthe current system date or a date in the future. Correct your entry orcancel processing.