[Koha] Upgrading database schema for

Sun Dec 19 00:17:52 NZDT 2021

Hi,
I'm trying to update the database of an instance and it's showing the
following error.

koha-upgrade-schema library
Upgrading database schema for library
Upgrade to 21.06.00.012  [21:15:15]: Bug 15067 - Add missing languages
ERROR - {UNKNOWN}: DBI Exception: DBD::mysql::db do failed: Duplicate entry
'AL-region' for key 'uniq_lang' at /usr/share/koha/lib/C4/Installer.pm line
738

How can I solve this?