SCS: You’re in...or not.

Carnegie Mellon joined the likes of the Massachusetts Institute of Technology (MIT) and Johns Hopkins University last Monday when about 800 applicants to the school’s master’s in computer science program were informed via email that they had been accepted, only to find out seven hours later in another email that the acceptances were a mistake.

Monday afternoon, many applicants received an email with “CMU Admissions Decision” in the subject line that told them, “Congratulations on your acceptance into the Master of Science program in Computer Science at Carnegie Mellon. You are one of the select few, less than 9% of the more than 1200 applicants, that we are inviting. We’re convinced this is the right place for you. Welcome to Carnegie Mellon!”

The email continues with a list of “bragging points” that applicants could take advantage of, such as Carnegie Mellon’s number one ranking in the field of computer science by U.S. News & World Report.

Seven hours later, applicants received a second email: “Earlier this morning, we mistakenly sent you an offer of admission to Carnegie Mellon’s MS in CS program. This was an error on our part. While we certainly appreciate your interest in our program, we regret that we are unable to offer you admission this year.” This email, sent by Frank Pfenning, president’s professor of computer science and department head, asked that recipients acknowledged that they got the second email.

Some mistakenly accepted applicants had already made plans in the seven hours between the two emails; Ben Leibowitz went out to dinner with his parents and called his relatives before he found out about the miscommunication.

“It was brutal. I didn’t get much sleep last night,” Leibowitz said to the Associated Press. “Now I have to clean up the mess. I’m calling all my relatives, I’m going, ‘I’m sorry it’s not happening.’ ”

In December, almost 300 applicants to Johns Hopkins University underwent a similar emotional rollercoaster when they were informed of their acceptance only to find out a few hours later that it was a mistake. MIT made a comprable mistake a year ago; a blog post from their Office of Admission blamed the mail delivery system that they use to email applicants.

Incidents like these go back years — in 2013, Fordham University falsely notified about 2,500 applicants that they had been accepted, and in 2012 the University of California, Los Angeles told almost 900 applicants the same.

According to a press release on the School of Computer Science’s website, Monday’s error “was the result of serious mistakes in our process for generating acceptance letters. Once the error was discovered, the university moved quickly to notify affected applicants.”

“We understand the disappointment created by this mistake, and deeply apologize to the applicants for this miscommunication,” the release continues, then going on to reassure applicants that no future mistakes take place.

“We are currently reviewing our notification process to help ensure this does not happen in the future.”