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 ('62c398f7e769622b6d20661046d828cd', -1, 1529672905, 1529672905, '36e08598', -2, 0, 0)

Line : 187
File : sessions.php