The aspiring entrepreneurs had gathered at the Bruce C. Bolling Municipal Building in Dudley Square this week for the rollout of the city’s new mobile Economic Development Center, a workshop and training seminar intended to lift up small businesses.

Mayor Martin J. Walsh encouraged attendees to take advantage of the opportunities, before he paused to point out the four vacant storefronts across Washington Street.

“A year from today, we want those storefronts to be filled . . . we have to do what we can to create those opportunities,’’ the mayor said, noting that the vacant space they were occupying in the Bolling would soon be a new jazz cafe he hopes will bring life to the neighborhood.

So goes the latest chapter in the effort to redevelop Dudley Square. It reads a lot like the last chapter, and even the one before it. The historic center of Boston’s black community, Dudley Square remains one of the city’s key targets for revitalization, but it has also proven to be among its most challenging, a troubling realization for officials as an economic boom has taken over other areas.

The city sees hope. New businesses, many of them minority owned, have invested in the neighborhood. And yet for every new business opening up, there are still vacant storefronts across the street. Six more businesses are about to close or have already shut their doors in recent months.

Dudley Square was once a vibrant commercial district — the most active shopping district outside Downtown Crossing — before urban renewal took over both neighborhoods in the 1960s. Downtown Crossing recovered, but Dudley Square never did.

“What will it take to get that level?’’ asked Biplaw Rai, a co-owner of Dudley Cafe, which has anchored the Bolling building since 2015. Business has improved, and is sustainable, Rai said, but is not quite near the neighborhood’s potential.

“We want to be there, at the end of the race,’’ Rai said.

On Thursday, the city hosted the mobile Economic Development Center at the same time that it sent code inspectors to various businesses in the neighborhood, checking out storefronts that have triggered complaints of blight. Inspectors handed out two code violations, and gave out several warnings, city officials said. Needles were found in a parking lot behind Walgreens on Washington Street. A Chinese restaurant, China Bo, was shut down last month because of evidence of rodents, said city inspectional services spokeswoman Lisa Timberlake.

Walsh, pointing to the row of storefronts with metal doors pulled over them, acknowledged after his speech last week that “you’re not bringing confidence to a community by keeping a storefront like that one looking across the street.’’

The proprietors of the Black Market pop-up retail market on Washington Street called for an “emergency round table’’ Saturday to gather business owners, landlords, residents, and city leaders to discuss what they called an “economic crisis’’ for the neighborhood.

The six businesses that are closing include the popular Haley House cafe, which called the move temporary last month while it devises a new business plan. That’s in addition to the closure last year of the Dudley Dough and Tasty Burger eateries.

“I think it’s alarming, and I think we need to have an ongoing meeting that addresses this,’’ said Kai Grant, the owner and chief curator of Black Market. “That’s the only way you’re going to stop the bleeding.’’

More than 30,000 people pass through the Dudley transit depot each day. The city spent more than $120 million to renovate the former Ferdinand building and merge it with two adjacent structures — what is known as the Bolling building— and four years ago moved its school administration there, bringing hundreds of employees to the area.

But many in the neighborhood say it will take time to resuscitate an area that was essentially abandoned for decades, following the closure of the Ferdinand, and the relocation in the 1980s of the elevated train system that ran through the neighborhood.

The struggle, neighborhood leaders and city officials said, has been getting people passing through Dudley Square to stay in the neighborhood. That, and improving the quality of life of people who already live there, some of Boston’s most economically vulnerable, so that they can support local businesses – by expanding job opportunities, and creating more affordable housing, they said.

“We’ve had some challenges, there’s no question about it, and we’ve got to make sure we’re doing everything we can to support small businesses districts like Dudley Square,’’ said Councilor Kim Janey, who represents the neighborhood, and attended Thursday’s workshops. “We’ve got to talk about what’s good with Dudley.’’

John Barros, the city’s chief of economic development, acknowledged that the revitalization of the neighborhood has been a struggle, but he said there has been no one cure-all.

Of the businesses that are closing, Barros said, their reasons vary: Haley House cited economic factors, while another business is actually the building owner, who wants to close up and rent out to someone else. Two of the stores are national chains, Payless and Ashley Stewart, that have given different reasons for leaving. And the owner of a local meat shop is returning to his home country.

Barros said the city’s efforts must focus on expanding economic opportunities for people who already live there (he pointed out that the mobile center’s first neighborhood rollout was in Dudley Square), while providing more affordable housing. The city recently requested proposals for housing and business development on four vacant parcels, he noted, and other development projects are already underway.

He said residents must have a say in the look of those developments, so that they remain neighborhood-centric.

And he pointed to the effort to bring restaurants and nightlife to the neighborhood, to bring residents and visitors to Dudley Square – and keep them there. That includes the opening of JazzUrbane Café, which will take over a 7,800-square-foot space in the Bolling.

“We kind of need to do this all at the same time,’’ Barros said. “We need to capture the flow of Dudley, while capturing the people who are there, who will shop, eat, and support local businesses.’’

Rai, of Dudley Cafe, said he looks forward to the new developments and the influx of residents, as long as they don’t change the character of the neighborhood. But little things matter as well, he said: the city could be better at replacing dead trees that line sidewalks; the area could use more trash cans; building owners could do their own part fixing up their storefronts.

“We need to have street lights that are working,’’ he said. “If we’re talking about bringing in new businesses, we should be ready to have them.’’

Milton J. Valencia can be reached at milton.valencia@globe.com. Follow him on Twitter @miltonvalencia.