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 ('87605101c4c6e44dce7fc98f6c1f9b35', -1, 1711709608, 1711709608, '03520321', 0, 0, 0)

Line : 187
File : sessions.php