Selection of logical system &1 is not allowed

Message type: E = Error

Message class: S_DX_BAPI - Messages for MDTB Workbench (Mass Data Transfer Using BAPIs)

Message number: 323

Message text: Selection of logical system &1 is not allowed

What causes this issue?

You cannot select the logical system here that is assigned to this
client.
The reason is that the data is written to a file using ALE/EDI outbound
processing but the ALE layer cannot send any IDocs from a system to
itself.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Select a different logical system.
If there is no suitable logical system, you can also create a logical
system here and generate the required Customizing.