Diagnosis
The logical system must be unique company wide. It must not be used byany other system in the ALE system group.
Therefore clients must be uniquely assigned to logical systems, thatis, a client can only be assigned to one logical system at a time.
More than one client can never be assigned to the same logical system.
This is true for both pre-productive systems and productive systems;the pre-productive system has to be a different logical system than theproductive system.

Recommendation
Assign a different logical system to the target client or leave the'Logical system' field for the target client empty.