A ‘Vote Here’ arrow, in three languages, point the way toward the polling station during Monday’s primary election. Elections officials acknowledged a glitch in the city’s mobile app is affecting an unknown number of voters’ party registration. (Keith Lane/For The Washington Post)

Voters reported multiple problems in casting ballots in the District on Tuesday, raising the possibility that technical issues could mar a citywide election for the second year in a row.

An unknown number of D.C. voters who went to the polls discovered that their party affiliation had changed — without their authorization.

Three voters interviewed by The Post said they were told their registration was no longer Democrat but “N-P,” meaning no party, preventing them from casting regular ballots counted on Election Day.

The Distrtict has a closed primary; only voters registered as Democrats, Republicans and D.C. Statehood Green party members can participate.

In a statement, Terri Stroud, acting executive director of the D.C. Board of Elections, blamed the problem on a technical glitch that seemed to be rooted in the board’s new mobile app.

“Some voters who updated their registration information through the mobile app may have experienced an unintentional change in their party affiliation,” he said.

Stroud’s statement was emailed to reporters who inquired, but no alert was posted on the board’s website or at polling locations.

But Jeremy Koulish, a web developer and political activist, said he alerted the board last week when he went to vote early in Columbia Heights and discovered he was no longer registered as a Democrat.

Koulish said he initially got little help from the board in investigating the problem and chose to publicize it Tuesday with a post on Facebook. “Then I got like 12 response from people saying they experienced roughly the same thing,” he said.

Koulish said he spoke with elections officials Tuesday and believes he isolated the problem. Koulish said he was able to replicate having his party erased by going onto the elections board’s app and changing his address. When a user changes the address, the app generates a new voter card. Unless the voter also updates party affiliation, the app assumes the voter is choosing “no party,” he said.

“It’s a massive bug to launch a web app with, it could be affecting a lot of voters,” Koulish said.

Michelle Kuchinsky, 26, found her party affiliation changed but she never used the app. She said she had switched her voter registration from Statehood Green to Democrat two years ago to vote in the city’s Democratic primary for mayor. A few months ago, she got a notice that said her registration had changed from Democratic to Statehood Green Party. Kuchinsky said she changed it back to Democrat and was able to vote successfully on Tuesday.

Jahar Abraham, who ran for a D.C. Council seat last year as a Democrat also said he found his party registration erased when he went to vote Tuesday.

Council member David Grosso (I-At large) said his wife observed a similar problem experienced at her polling place.

“I’m worried this could be widespread,” Grosso said. “And it’s something that people wouldn’t be looking for, why would you ever check to make sure your party hadn’t changed on you?”

In its statement, the board said that if a voter believe a party affiliation is incorrect, that voter can fill out a special ballot. Special ballots will be counted Friday, a spokesman said.