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 ('2006f8de7c3b7d7df2a099b7f9d266f1', -1, 1711669576, 1711669576, '3437d6ec', -4, 0, 0)

Line : 187
File : sessions.php