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 ('81acbd44cc12dd66b3703db07472a8fb', -1, 1756934966, 1756934966, 'd849d821', 1, 0, 0)

Line : 187
File : sessions.php