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 ('771b32819a1a76dfd715e14aff4e8bb9', -1, 1711719675, 1711719675, '2ccad169', 6, 0, 0)

Line : 187
File : sessions.php