Country ID &1 is not a valid ISO code

What causes this issue?

&V1& is an <DS:DE.INTCA>ISO code</> that does not exist within the SAP
country table.

System Response

Error message

How to fix this error?

Check whether the code &V1& is defined as an ISO code for a country key
in table T005 (countries).
<DS:TRAN.OY01>Proceed</>
If not, enter the ISO code that is valid for the desired country.

Error message extract from SAP system. Copyright SAP SE.