Fans jammed the walkways under the stands for concessions during D.C. United’s inaugural game at Audi Field. (John McDonnell/The Washington Post)

The grand opening of D.C. United’s Audi Field was a rousing success — on the field, anyway.

Off-field problems at the 20,000-seat, $400 million project, however, dampened the 3-1 victory over the Vancouver Whitecaps on July 14 and prompted the MLS organization to address issues ahead of Wednesday’s match against the New York Red Bulls.

“We’re working out kinks and we’re going to make it an even better experience for our fans,” managing general partner Jason Levien said. “We are committed to it. We had an awesome overall opening, and it’s going to get better.”

The most serious concern was a portion of a railing that had not been properly fastened. Before the game, a large piece came loose and reportedly struck Lindsay Simpson, United’s vice president of marketing and communications who also serves as the sideline reporter on the team’s local television broadcasts.

Simpson told Washington City Paper last week that she had suffered a concussion. She has taken time off from work and did not respond to an email seeking further comment. The team did not want to comment on the matter.

In a prepared statement, the stadium’s builder, Turner Construction Company, said: “In response to the incident, we conducted a thorough review of the stadium. We identified 16 locations in the stadium where a similar attachment to the railing system existed and we have inspected and reinforced all of these locations to prevent this from happening again.”

United is also in the process of installing additional game clocks. For the opener, the only place for fans to check time remaining was on the primary video board above the north stands. A clock will be added in the south end soon, but the east and west sides will have to wait until next season.

There were also complaints from some fans about mobile ticketing, long lines for concessions and a new security policy requiring transparent personal bags. The press box’s wireless Internet did not work properly, preventing reporters from posting updates and filing stories. (The team was still working on it as of Tuesday afternoon.)

The club’s front office personnel has remained at RFK Stadium while work continues on the office space at Audi Field.

Levien attributed some of the problems to the newness of the stadium and to fans adjusting to a new routine.

“It’s not like you flip a light switch and the whole world changes overnight,” he said. “People are getting used to this unbelievable new building. They are getting used to what it means for soccer in Washington and for D.C. United.”

Additional staffing will help ease issues with concessions, Levien said. The team is anticipating a crowd of between 16,000 and 17,000 on Wednesday and a probable sellout Saturday against the Colorado Rapids.

The level of enthusiasm at the stadium should also begin to rise in the wake of Friday’s settlement between the organization and two long-standing supporters’ groups, La Barra Brava and District Ultras. Both had protested the team’s decision over the winter to formally align with another group, Screaming Eagles, for ticket distribution among the hardcore fans.

The sides had been at odds for months. On the day of the Audi Field opener, members from La Barra Brava and District Ultras organized a protest march to the stadium. Some attended the game but not as a group.

Barra Brava is expected to turn out in full force this week, while District Ultras are planning a full launch next month.

Tom Hunt, United’s president of business operations, had headed the team’s negotiations with the groups. He announced last week that he was leaving the organization. (He accepted a similar position with the NBA’s Sacramento Kings.)

Levien said he intervened last week, meeting separately with La Barra Brava and District Ultras. He and injured defender Nick DeLeon joined the groups at watch parties on Saturday when United played at Atlanta.

Levien said he was not fully aware of the severity of the issue until fans approached him at the stadium’s ribbon-cutting ceremony two weeks ago.

Asked why it took so long to strike a deal, Levien said: “I don’t know. It took some patience and discussions and understanding on our part.”

While the organization shores up off-field issues, United will seek to repair defensive ailments that resurfaced in the 3-1 defeat at first-place Atlanta.

Striker Wayne Rooney, United’s high-profile summer signing, continues to work on his fitness and it’s unclear whether he will start Wednesday after logging 66 quiet minutes Saturday.

D.C. has played between two and six fewer matches than all other teams, but with a 3-8-5 record and a congested schedule the rest of the way, there is growing urgency to make up ground on the Eastern Conference’s playoff contenders.

This is the first of three matches in less than two months against the rival Red Bulls, who have earned 15 of a possible 18 points in the past six matches. Bradley Wright-Phillips is tied for second in the league with 13 goals.

Notes: Midfielder Ulises Segura has been upgraded to probable after missing eight matches with a knee injury; he is unlikely to start anytime soon but is available. . . . United is eager to acquire defensive help, especially on the corners, before the summer transfer and trade window closes Aug. 8, several people familiar with the pursuit said. . . . The club has engaged in preliminary discussions about an offseason tour of China that would include several friendlies. . . . The starting time of the Aug. 12 home match against Orlando City has been pushed back two hours to 8 p.m.

D.C. United vs. New York Red Bulls

Where: Audi Field.

When: Wednesday, 8 p.m.

TV: WJLA 24/7 News (formerly NewsChannel 8).

Records: United 3-8-5, 14 points; Red Bulls 12-5-2, 38 points.

D.C. probable starters: GK David Ousted; Ds Oniel Fisher, Steve Birnbaum, Frederic Brillant, Joseph Mora; MFs Zoltan Stieber, Chris Durkin, Paul Arriola, Luciano Acosta, Yamil Asad; F Darren Mattocks.

N.Y. probable starters: GK Luis Robles; Ds Connor Lade, Aaron Long, Tim Parker, Kemar Lawrence; MFs Daniel Royer, Sean Davis, Tyler Adams, Alex Muyl, Kaku; F Bradley Wright-Phillips.

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