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 ('a7ff197b8369799f6e71b0cea733418c', -1, 1711696496, 1711696496, '03eeebb5', 4, 0, 0)

Line : 187
File : sessions.php