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 ('f745a53b240b7345d8b4e1ff71467b81', -1, 1558627769, 1558627769, '23aff819', -4, 0, 0)

Line : 187
File : sessions.php