Group currency translation not allowed with document type &1

What causes this issue?

You can only select the Translate Group Currency flag if the document
type has posting level 01 or 10, and if the document type posts in
group currency and at least one more currency (transaction or local
currency).

System Response

Your settings cannot be saved.

How to fix this error?

Either deselect the flag, or select the currency indicators as
documented.

Procedure for System Administrators

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

Error message extract from SAP system. Copyright SAP SE.