Hello! How to fix this error? 21.05 to 23.05 Update errors : - Upgrade to 21.12.00.013 [10:55:03]: Bug 29605 - Resync DB structure for existing installations ERROR: {UNKNOWN}: DBI Exception: DBD::mysql::db do failed: Duplicate entry 'ar' for key 'PRIMARY' at /usr/share/koha/lib/C4/Installer.pm line 741 -- J.Baatarsuren Dean of libraries Mongolian National University of Education <https://www.facebook.com/mubislibrary> Улаанбаатар хот, Сүхбаатар дүүрэг VIII-р хороо ,Улаанбаатар- 48 , Бага тойруу-14, МонголУлс-210648 Утас 77775115-1077, 89119934 Web: http://monkoha.com/ <http://library.mnue.mn/>