Zohaib Jailani didn't hide his disappointment after he was told York University had accepted him as a student by mistake.

"I hate university already :)" he tweeted Tuesday. His tweet was 'liked' nearly 3,000 times as of Wednesday night.

On Monday, Jailani received an email from York saying, "Congratulations! You are being offered admission to York University."

A day later, he received another email saying, "You recently received an offer of admission email from York University. Please accept our apologies — we made a mistake ..."

Jailani was one of 500 students who received the bad news Tuesday.

York University's Joanne Rider explained what led to the error in an email to CBC News Wednesday night.

"There was a processing error whereby approximately 500 individuals were sent emails indicating they had been accepted for admission to York," Rider wrote. "This occurred immediately after the university had sent emails to acknowledge their applications had been received."

Rider said the school has apologized to the students. She added that they've been informed their applications are under consideration.

"We know this is an important decision point for students and families," she said. "It was explained that the university needs to receive marks to make offers and this will occur in mid to late February.'