Acct group for plant profile & uses internal no.assignment, not possible

What causes this issue?

The plant profile refers to an account group for which internal number
assignment has been defined.
Only external number assignment is possible when you create a plant.

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

System Response

How to fix this error?

If you are authorized, you can assign the account group in question a
number range with external number assignment.
IF &DEVICE&='SCREEN'
<ds:TRAN.WOC1>Proceed</>
ENDIF

Error message extract from SAP system. Copyright SAP SE.