phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '21a4818bf4925cd3f5c08d3407b7b87d' for key 'phpbb_sessions.PRIMARY'

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('21a4818bf4925cd3f5c08d3407b7b87d', -1, 1765499461, 1765499461, 'd849d8b4', -4, 0, 0)

Line : 187
File : sessions.php