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 ('3488bb9872d557f2b9a32a3881a7e1c9', -1, 1711631763, 1711631763, '03e6a2ee', -4, 0, 0)

Line : 187
File : sessions.php