SQL-DATABASE ERROR

Database error in WoltLab Burning Board (2.3.6): Invalid SQL: SELECT * FROM bb1_info_charaktere WHERE (charakter = 'M��hlenhofbauer' OR (charakter LIKE '%M��hlenhofbauer%' AND charakter LIKE '%;%') OR charakter LIKE 'M��hlenhofbauer%[%') AND synchronsprecher != '---'
mysql error: Illegal mix of collations (latin1_swedish_ci,IMPLICIT) and (utf8mb4_unicode_ci,COERCIBLE) for operation '='
mysql error number: 1267
mysql version: 10.5.15-MariaDB-0+deb11u1-log
php version: 5.6.40
Date: 14.08.2022 @ 04:52
Script: /hoerspiele.php?action=search&char=M%EF%BF%BD%EF%BF%BDhlenhofbauer
Referer: