During the course registration period for this semester, students complained about the lack of seats in mandatory courses and online registration system due to its technical errors. Even worse, some students who connected to the registration site using Internet Explorer failed to sign up for their pre-reserved courses. The reason for the system error should have been given to students as quickly as possible. I think it the best way to solve these problems if the administration makes the online service better by testing the server regularly to prevent the same errors, and assigns extra seats for students who must take mandatory subjects.