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 ('1c60f9b4bbd61b6ba7baf9f2a97eb48e', -1, 1711663776, 1711663776, '03ef779f', -9, 0, 0)

Line : 187
File : sessions.php