phpBB : Critical Error

Error creating new session

DEBUG MODE

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

INSERT INTO pcxhpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('80b2423fc64e59322672f48d02131f6c', -1, 1568951418, 1568951418, '0350044c', 2, 0, 0)

Line : 186
File : sessions.php