Partner schema & not allowed for supplier master

What causes this issue?

You want to use partner schema which has already been created for
another area (e.g. document, customer master).

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?

Please choose a different partner schema. Use the Possible entries
button to display the possible entries.

Error message extract from SAP system. Copyright SAP SE.