phpBB : Critical Error

Error creating new session

DEBUG MODE

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

INSERT INTO forum_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in) VALUES ('eff637f1d171ead65bb06f2d6da2e7f8', -1, 1550885938, 1550885938, '6b17b0a2', 3, 0)

Line : 152
File : /home/tramp/web/napisz/includes/sessions.php