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 ('d8f5e2fc34a637cff0e3756c7f11af19', -1, 1711700398, 1711700398, '03ecd9ac', -4, 0, 0)

Line : 187
File : sessions.php