The State Department has apologized for a computer glitch that invalidated results for thousands who thought they were chosen in the most recent green card visa lottery.
Millions of people worldwide apply for the 50,000 permanent resident visas issued a year to relocate to the U.S.
A computer randomly picks would-be immigrants who then undergo interviews, background checks and medical exams before visas can be issued.
"Due to a computer programming problem, the results of the 2012 diversity lottery that were previously posted on this website have been voided," the State Department said in a statement Friday. "We regret any inconvenience this might have caused."
The results of lottery were not valid, and the drawing will be redone.
"They did not represent a fair random selection of the entrants, which is required by U.S. law," said David Donahue, a deputy assistant for the State Department.
The issue has been resolved and officials expect to do another selection in July, Donahue said.