SAP Message AP225 - Assignment already exists - you cannot make assignment again

Diagnosis
You tried to assign a measure or appropriation request to an investmentprogram position. However, the system found that the measure orappropriation request had already been assigned to the programposition in the past, and was assigned to the corresponding position ofthe investment program in the new approval year during the fiscal yearchange.
Therefore, it is not possible to assign the position again to theprogram position in the old approval year.

System Response
The assignment cannot be made.