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 ('5d785cafb44774b8c81f3c137ed9532e', -1, 1561449060, 1561449060, '36a3d595', 22, 0, 0)

Line : 187
File : sessions.php