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 ('1da74652334d912c1d9b4de83d9b6304', -1, 1540033314, 1540033314, '36c637a7', 25, 0, 0)

Line : 189
File : sessions.php