SQL-DATABASE ERROR

Database error in WoltLab Burning Board (2.3.6): Invalid SQL: UPDATE bb1_guthaben_bank SET akt_jahr='2023', crashtag='25', boersencrash='0',boersencrashdate = '', boersencrashaktienwert='', boersencrashprozent='',boersencrashaktienwertneu='' WHERE bankid='1'
mysql error: Incorrect integer value: '' for column `web8_corelith_db`.`bb1_guthaben_bank`.`boersencrashaktienwert` at row 1
mysql error number: 1366
mysql version: 10.5.21-MariaDB-0+deb11u1
php version: 5.6.40
Date: 02.12.2023 @ 02:59
Script: /hmportal.php
Referer: