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 ('715ae8833262624243fcffee928bf0c7', -1, 1550421345, 1550421345, '365acce9', 1, 0)

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