Diagnosis
You have entered at least two of the CO account assignments, costcenter , order, or PSP element in the cost distribution.

System Response
In theory, this is possible, but in an ALE distribution scenario,whereby the account assignment check is carried out remotely in theaccounting system, accounting must run in an SAP release status of 4.6or higher. This is not so in your case.

Procedure
Assign every line of cost distribution only to a cost center, order ora PSP element.