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 ('0a2f9e07330844ad48e04ed4d328d7af', -1, 1558627763, 1558627763, '23aff819', 2, 0, 0)

Line : 187
File : sessions.php