NEW HAVEN, Conn. – A popular Yale professor resigned this week after backlash from some students about a letter she penned about politically correct Halloween costumes.

Erika Christakis, associate mater of Silliman College, emailed students Oct. 30 to criticizing some who had called for students to refrain from culturally inappropriate Halloween costumes.

MORE NEWS: Know These Before Moving From Cyprus To The UK

“Is there no room anymore for a child or young person to be a little bit obnoxious, a little bit inappropriate or provocative or, yes, offensive?” she wrote, according to CBS News. “American universities were once a safe space not only for maturation but also for a certain regressive, or even transgressive, experience; increasingly, it seems, they have become places of censure and prohibition.”

The letter prompted hundreds of students to protest the alleged racially insensitive email, as well as other purported racial injustices at Yale. A campus activist group called Next Yale also called for the removal of Christakis and her husband, Silliman College master Nicholas Christakis, from their leadership positions, among other things.

Several dozen Yale faculty members countered with a letter of support for the Christakises, alleging the campaign against them diminishes the “educational variety” at Yale.

Yale College president Peter Salovey and dean Johnathan Holloway also wrote in a email to Silliman students that they “fully support” the coupe’s mastership.

It apparently wasn’t enough.

According to the Yale Daily News:

In an email to The Washington Post, Christakis said she cancelled her spring course “The Concept of the Problem Child” — which drew large crowds during shopping period when she also taught it this fall — in response to a campus climate not “conducive to the civil dialogue and open inquiry required to solve our urgent societal problems.”

MORE NEWS: How to prepare for face-to-face classes

Nicholas Christakis also plans to take sabbatical leave next semester. The decision means Erika Christakis’ popular courses – “The Concept of the Problem Child” and “The Growing Child in Global Context” – are canceled for the spring, as is Nicholas Christakis’ well-attended lecture “Health of the Public,” according to the site.

Holloway told the Yale Daily News Christakis is paid per course as a lecturer, and made the decision “on her own” to take next semester off.

“I don’t have much to add to her decision,” he said.

The Penguin Books website shows Erika Christakis will release a book “The Importance of Being Little” on Feb. 9 and will spend the spring at book events across the country this spring.

The announcement of Christakis’ departure was a total bummer for student Leah Meyer, a sophomore who was hoping to take “The Concept of the Problem Child.”

Meyer questioned why Christakis, an advocate for open debate, is leaving the conversation about race and free speech she sparked this semester.

“That, to me, is frustrating,” Meyer said. “I’m not saying she made the wrong decision, I’m just saying that it’s unfortunate. Just because I think that she should remain on faculty and continue to teach does not mean that I condone all her actions.”

A black student who took Christakis’ seminar this spring but did not want to be identified told The Washington Post he enjoyed her course and said she cares about students.

“The concept of the problem child, and the global child, they’re very important topics, and Yale doesn’t have many classes on education and child development,” he said. “To lose that is a very big detriment to students interested in these issues, and the class could have been getting better. And if she was learning from the events happening on campus, and if she went into it trying to make it better for all communities, that would have been better for her and better for the school in general.”