Harvard Square’s most prominent vacant property is still dark. Now officials want answers from its owner.

City Councilors last week took the uncommon step of formally asking Chan, along with the owners of 22 other long-vacant properties in the square, to appear in front of them to account for the holdup.

“It’s been too long,” said Councilor Marc McGovern. “It’s time for him to do something.”

Chan, a Harvard-trained scientist and private equity and venture capital investor, didn’t respond to requests for comment. Dan White, the manager of the company controlled by Chan, said in a statement that it remains “fully committed to bringing forward a new plan to develop the site."

“Ultimately, our goal is to create a vibrant space on Church Street by developing a venue that will create jobs, help drive visitors to Harvard Square and, most importantly, bring the site back to life and carry it into a new era,” White said.

But many of his neighbors are getting impatient.

The theater isn’t much to look at now, and in truth was never an architectural marvel. From the street, it’s mostly just a long, tall brick wall.

But what it lacks in curb appeal, the nearly 100-year-old Harvard Square Theatre makes up for in nostalgia, and, say many with fond memories of it, potential.

It was a cinema back in Hollywood’s Golden Age, when its entrance fronted Massachusetts Avenue. It hosted live music of the likes of Bruce Springsteen, The Clash, David Bowie, and Tom Waits. For years, it was a long-term home for superfans of the cult film “The Rocky Horror Picture Show,” and people came from across Greater Boston to get glammed up in fishnets and leather for the shows.

By the 2010s, when it was owned by the multiplex chain AMC, it had seen better days. It closed in 2012 and has never reopened.

Lots of people had their cultural education there, said Ned Hinkle, who grew up seeing both blockbuster and art-house films in the quirky multiscreen theater, and is now creative director at The Brattle, a single-screen theater that is the last of its kind in Harvard Square. They’ve held out hope it isn’t gone for good.

“Since it closed, we’ve been fantasizing about everything that we could do in that space,” Hinkle said. “There’s such a history in that building with all different kinds of entertainment, and it’s sort of crazy that it’s just sitting there rotting.”

When it closed, AMC sold it to real estate titan Richard Friedman, who intended to renovate the space and keep the lights on.

“We didn’t buy it to flip it. We bought it to run it as a theater if we could,” Friedman said in a recent interview.

But he found the aging building, which by then needed significant investment to bring it up to code, was too far gone to save without losing lots of money.

“We couldn’t figure it out, which is not our style, because we usually figure out complicated problems,” said Friedman, whose firm built the One Dalton tower in Boston, and the Charles and Liberty hotels. “I care about Harvard Square and I care about the culture here. It was just a tough nut.”

He sold it two years later to Chan, who owns multiple properties in the square and remains a major figure at his alma mater: The Harvard T.H. Chan School of Public Health is named after his late father, after Gerald Chan’s Morningside Foundation gave the university a $350 million donation.

Other parcels under Chan’s control have flourished. The Cambridge Historical Commission has lauded his work restoring properties such as 40 Bow Street.

Chan once proposed a showstopper of a plan for the theater. In 2018, he devised a scheme that had wide support in the city, which would see the theater replaced by an office building with a hulking LED screen, with room for a two-screen movie theater.

It stalled. The COVID pandemic brought projects of all sizes to a halt and upended the market for office space. The movie theater business slumped, and the return of viewers to in-person screenings has been uneven. Actor and onetime Cantabrigian Casey Affleck publicly expressed interest in taking over the theater. That fizzled as well.

The Harvard Square Theatre has remained dark.

Meanwhile, its absence has had an impact on business in the square, said Denise Jillson, executive director of the Harvard Square Business Association, who said the theater once brought 1,000 visitors a day into the neighborhood. The commercial district has 11 storefronts that have been vacant for at least six months, according to a database created by the city.

Jillson ideally would like to see entertainment return to the theater — movies, live performance, or both — so it can again be a draw to the square. But at this point she’s not picky.

“Anything is better than what we have now, which is nothing,” Jillson said. “Certainly what’s not helpful is buying properties and not developing them, and not understanding the negative impact of leaving a building or space empty.”

White, Chan’s business partner, didn’t respond to questions through a spokesman about their specific intentions with the property and whether they would commit to including an arts component in any redevelopment.

It’s expensive to do nothing. Last year alone, about $190,000 in taxes were assessed on the property, according to city records.

Still, it’s not an ideal time to be making big construction plans, experts say, as markets swing wildly over tariff talks, and developers confront uncertainty about the kinds of properties that will be profitable to build, especially in a place like Harvard Square.

“The obstacles are probably the highest they’ve been in several decades,” said John DiGiovanni, who also owns properties in the square, including The Garage shopping center, as well as the building that houses music venue The Sinclair.

But that’s no excuse for letting a historic theater fester in the heart of Harvard Square, DiGiovanni said. If anyone can solve the problems this property presents, he said, it’s Chan.

“He’s a leader in all sorts of areas. He’s a model in the biotech world. We need that kind of focus with his real estate,” DiGiovanni said. “This is a really special, unique urban district that deserves good stewards.”

On the street outside the old theater on a recent afternoon, it was surprisingly quiet, despite being rush hour. A man spread out a flattened cardboard box to take a load off, lounging next to a fading collage of painted movie characters Robin Williams’s “Mrs. Doubtfire” and R2-D2, from “Star Wars.” Above, the Beatrice Sargent “Women’s Community Cancer Project” mural that clings to its exterior wall showed signs of falling apart — neighbors say a chunk of it recently clattered onto the sidewalk.

On the old marquee, which juts over Church Street, reads “lifting as we climb,” and “onward and upward we go.”

The faded scene suggests otherwise.

Spencer Buell can be reached at spencer.buell@globe.com. Follow him @SpencerBuell.