Identificat. type &1 is language-dependent; entry valid for all languages

What causes this issue?

The identifier for the identification type is language-dependent. That
means that the system expects you to enter a language indicator such as
"E" or "F".
If you do not enter a language indicator, the identifier is valid for
all languages.

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?

Error message extract from SAP system. Copyright SAP SE.