phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '-1' for key 'session_user_id'

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('f72cd65a4e5ef4608610c32a2e94b3d0', -1, 1711679814, 1711679814, '23a96bb1', -9, 0, 0)

Line : 187
File : sessions.php