& & and & & are identical!

What causes this issue?

In the area of conversion of export data into import data, you have
attempted either
to maintain a reference country that is the same as the country itself
or
to include an entry in the conversion object where the country of
departure is the same as the country of destination.

System Response

The system only allows this entry for conversion of export data into
import data and vice versa, not for maintenance of reference countries.

How to fix this error?

Enter different countries.

Error message extract from SAP system. Copyright SAP SE.