Status of error #4640981: new

"Duplicate entry 3.128.153.31 for key user_name (INSERT INTO `users` (user_name) \n VALUES (3.128.153.31);)"
"Duplicate entry 3.128.153.31 for key user_name (INSERT INTO `users` (user_name) \n VALUES (3.128.153.31);) from mysql->insert"

Program trace:
#0 /var/www/default/src/main/php/model/user/user.php(414): mysql->insert(user_name, 3.128.153.31, -3)\n#1 /var/www/default/src/main/php/model/user/user.php(222): user->save(-2)\n#2 /var/www/default/http/view.php(49): user->get(-1)\n#3 {main}