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 ('a6a41b3864b0a5d94d0cd4c7228e6b5d', -1, 1566129089, 1566129089, '12ce0fd7', -2, 0, 0)

Line : 187
File : sessions.php