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 ('dc0a6a5dadd1d6525b7faf8af1db51bb', -1, 1560792808, 1560792808, '36912d8f', -6, 0, 0)

Line : 191
File : sessions.php