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 ('72801ab7c9eda56357c9b50950daa791', -1, 1566115409, 1566115409, '12e835e7', -10, 0, 0)

Line : 187
File : sessions.php