SQL-DATABASE ERROR

Database error in WoltLab Burning Board (2.3.6): Invalid SQL: INSERT INTO bb1_sessions (sessionhash,userid,ipaddress,useragent,lastactivity,request_uri,styleid,langid,authentificationcode) VALUES ('ef419969d22042c57fc01e9b14608bf5','0','3.12.151.153','Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.c','1716259315','calendar.php?sid=1ff1ce3a227a062769159f9374f257a1','0','0','')
mysql error: Duplicate entry 'ef419969d22042c57fc01e9b14608bf5' for key 'PRIMARY'
mysql error number: 1062
mysql version: 5.7.42-log
php version: 5.6.40
Date: 21.05.2024 @ 04:41
Script: /calendar.php?sid=1ff1ce3a227a062769159f9374f257a1
Referer: