It was a sucker punch, The Los Angeles Times said.

After the University of California, Irvine, withdrew admissions offers for nearly 500 students, the outrage spread far beyond the campus community.

But the practice is not unusual among California’s public universities.

According to figures from the University of California, since 2015 more than 4,000 applicants to UC campuses, aside from Irvine, have had their offers of admission rescinded — the bulk of them over paperwork problems.

Among the most notable examples was two years ago, when the University of California, Santa Cruz informed more than 500 incoming freshmen that their offers were canceled because they missed a deadline to send in their transcripts.

An outcry led the campus to reinstate many of the students and adopt more forgiving admissions policies.

Universities sometimes underestimate how many students will accept their offers of admission, putting them in a bind to create room. Critics say that too often campuses have resorted to looking for any excuse to revoke offers.

High school guidance counselors in California now drill teenagers on the seriousness of deadlines in college admissions. Still, a number of the roughly 100,000 students accepted into the UC system each year are bound to slip up.

“Those deadlines — we tell students all the time, ‘They are the smallest thing, but it’ll make or break whether you get into the college,’” said Bernadine Diele, who advises high school students in Merced. “And it has nothing to do with your competitiveness.”

Last year, the University of California, Riverside rescinded more than 300 admission offers over missing paperwork; UC Merced revoked about 160; and UC Davis nearly 100.

Jill Orcutt, Merced’s associate vice chancellor for enrollment management, said incoming freshmen were repeatedly reminded about the transcripts deadline. Many of those who fail to meet it, she suggested, most likely had no real intention to attend the university.

Irvine initially defended the decision to cancel so many acceptance offers, then apologized after a drumbeat of news stories in which students said their lives had been upended.

As of last week, roughly 280 of the students had been reinstated. Others were under review.

Assemblyman Phil Ting, a Democrat, has been a vocal critic of what he described as a “gotcha game” in UC admissions.

He’s pushing Janet Napolitano, the system president, to adopt policies across all 10 campuses that ensure young people are given every chance to meet their enrollment conditions.

“These are people’s lives,” Ting said. “Going to college is a transformative experience and to deny that over some paperwork seems to me mind-boggling.”