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 ('9042b2ff393541468331187a9a8a3911', -1, 1542518964, 1542518964, '36a31439', 0, 0, 0)

Line : 193
File : sessions.php