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 ('b2d7f29674133309b3a50884f9f10202', -1, 1566649968, 1566649968, '22ec2692', -2, 0, 0)

Line : 187
File : sessions.php