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 ('192cb8bd2c1fe561e36de091db8b1b92', -1, 1560841100, 1560841100, '365b476c', -8, 0, 0)

Line : 187
File : sessions.php