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 ('02e7f237c671e7af89aca437aeae00c9', -1, 1711719903, 1711719903, '03dba7a3', -4, 0, 0)

Line : 187
File : sessions.php