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 ('51f30d208ea024e971532015458d9504', -1, 1560711887, 1560711887, '12d7a113', -8, 0, 0)

Line : 191
File : sessions.php