Table T002 contains unused language &1 (read long text).

What causes this issue?

The language &V1& is part of the so called system languages (contents of
table T002). As such it is visible in many different place e.g. as entry
in the search help used for languages.

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

But the language is not an active language of the current I18n
configuration. Therefore it might makes sense to delete the language to
avoid superfluous content from language selections. The decision to
delete the language from table T002 depdends on how the language was
used before. In any case it is added again to T002 in case of a new
configuration of that language.
Note: this check/message only appears for new Unicode languages. There
are 41 legacy language codes which shouldn't be removed from the list of
system languages.

System Response

How to fix this error?

In RSCPINST select the menu "Edit -> Unused Languages" to delete the
language &V1& from T002 / T002T.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.