As the first day of shopping period opened at Yale College, the 1,418 students who had entered their tentative course schedules on Yale Bluebook+ found the website blocked on University servers.

The application, designed by brothers and co-developers Peter Xu ’14 and Harry Yu ’14, used data from Yale’s course information database to offer students a convenient way to compare class evaluations and ratings, Xu said. Though the program has been available for students’ use for the last three semesters, it was only last Wednesday that the brothers were approached about the website. University Registrar Gabriel Olszewski sent them an email citing concerns that the website was “making YC course evaluation available to many who are not authorized to view this information,” asking how they obtained the information, who gave them permission to use it and where the information is hosted. In subsequent exchanges Olszewski raised concerns over the website’s unauthorized use of the Yale logo and the words “Yale” and “Bluebook,” the prominence of class and professor ratings, the application’s accessibility to non-undergraduates, and the fact that it wasn’t hosted on Yale’s servers. When the brothers met with Olszewski two days after the first email, they said they were told that the website had to be shut down.

Olszewski did not respond to multiple requests for comment Monday.

“This was very sudden,” Xu said. “We thought they’d work with us to resolve the problems. But they were very straightforward and asked us to shut it down, right at the start of shopping period when a lot of students had worksheets on it.”

Rather than taking the website down immediately, Xu and Yu looked to the case of another popular shopping website, Yale BlueBook. That website encountered similar issues when it first came out, but the site’s designers talked with the administration, and Yale eventually purchased the website. Hoping to make a similar compromise, Xu and Yu said they presented several new mockups of the website to the administration. The revised versions changed the website’s color scheme, removed the words “Yale” and “Bluebook,” changed its name to “CourseTable,” and took out the option of sorting classes by ratings. However, the brothers did not hear back from the administration until Monday, when the website was suddenly blocked without notice, Yu said.

The reaction among the student body was primarily confusion, said Stuart Teal ’14, a member of the Student Technology Collaborative.

“I feel like the shutdown was done by the administration very suddenly and immaturely, without any communication or transparency at all,” he said.

In an effort to clarify the situation, Xu posted in several popular campus Facebook groups, explaining that the administration had blocked the website and that he and Yu were working to email students their worksheets as soon as possible.

Quinn Zhang ’14 said he has found the shutdown to be a great inconvenience.

“Most people have their shopping lists planned out on YBB+ and have to shop by memory or email Harry [Yu] or Peter [Xu] for a copy of their schedules,” he said.

Xu and Yu eventually emailed all students who had planned a worksheet on YBB+ a copy of their individual schedules — an effort which required them to buy a subscription to an outside mailing service.

The Yale College Council, which has helped publicize other student technology initiatives in the past, including Yale BlueBook, had been planning on promoting YBB+ before the shutdown occurred, said YCC President Danny Avraham ’15. The YCC is now engaging with the administration in an effort to aid Xu and Yu, he added.

“The response from the student body has been completely supportive,” Xu said, citing dozens of emails he and Yu have received.

Xu and Yu said based on their interactions with the administration they believe that out of all the concerns listed about their site, the most pressing one to the administration is the prominent public display of course ratings. Yale BlueBook, Yu said, has the exact same functionality as their site, except that YBB+ sorts classes by ratings and displays averages much more clearly. He believes that this is the reason the administration was unwilling to compromise with him and Xu the same way it did with Yale BlueBook’s developers.

Though they are both upset about the shutdown, Xu said they understand the administration’s concerns and will comply with all of the administration’s demands. This decision was heavily guided by the administration’s threat of disciplinary action, Yu added.

“We’ve tried so hard to work with them to minimize the impact of this shutdown, and they know we’re open to doing anything to keep the site open to students,” Xu said. “I understand where they’re coming from, but I just think they’re doing it the wrong way. There are better ways to do it.”

In the last week, YBB+ has received 2,983 unique visitors.