phpBB : Critical Error

Error creating new session

DEBUG MODE

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

INSERT INTO luigi_phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin, is_robot) VALUES ('b8cab1d883a4a616de7cce0b798eeb5a', -1, 1561491258, 1561491258, '22cc2b0b', -8, 0, '0', '0')

Line : 175
File : sessions.php