“On many of the machines you could only see one party on the ballot, sometimes two or three, but you could never see all of the parties on a ballot,” said Mr. Cabral.

As the extent of the problem became clear, election officials suspended the vote. “The electronic vote failed us that morning,” Julio César Castaños Guzmán, the electoral board president, told party delegates days later.

Officials also admitted that, at least a day before the election, they knew of a problem with the voting machines but thought it would be easily fixed.

“We were warned, but not of the magnitude of the problem,” Mr. Castaños Guzmán said. Referring to people who helped set up the system, he said, “They told us it was an issue that could be fixed the second the machines were installed.”

How did the government respond?

After suspending the vote, the electoral board scheduled a new election for March 15, 30 days after the original date, as the Constitution mandates. The board said polling places would use only paper ballots. Any ballots that were submitted in February would be destroyed.

The board also suspended its national technical director and enlisted the Organization of American States, a United Nations-like group that represents 35 Western Hemisphere nations, to audit the automated voting system.

“This audit will be complete and binding in its results,” the O.A.S. said in a statement.

The Dominican Republic also faces a presidential election on May 17, increasing the pressure to make sure its election system works and is trusted.