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 ('08c5b1ab4bc7b5a390e9cd4f14d0be6a', -1, 1711647844, 1711647844, '03e3ef09', -4, 0, 0)

Line : 187
File : sessions.php