All Georgia counties use voting systems made by Dominion. The system having problems in Gwinnett is a batch scanner made by Dominion that is used to rapidly scan large batches of absentee ballots.

Sorenson told the Journal-Constitution that the batch scanner in Gwinnett failed to read at least one ballot in each of 3,200 batches of ballots, and that the county would have to rescan the ballots and then manually review them to ensure an accurate count.

The snag emerged hours after a different technology glitch halted voting Tuesday morning in Georgia's Morgan and Spalding counties.

Marcia Ridley, elections supervisor at the Spalding County Board of Election, earlier told POLITICO that the problem in her community was caused by its electronic pollbooks.

In addition to its Dominion voting machines Georgia uses electronic pollbooks made by KnowInk. The state deployed both systems in every county for the first time this year after replacing its previous 20-year-old electronic voting systems.

Ridley said one of the vendors uploaded an update to her county's pollbooks the night before the election, without notifying her. The update caused a glitch that prevented the pollbooks from being used. The KnowInk pollbooks are used to sign in voters, and also to program smart cards that are inserted into Dominion voting machines to display a digital ballot onscreen for voters.

“That is something that they don’t ever do. I’ve never seen them update anything the day before the election,” Ridley said, speaking about the upload. Ridley said she did not know what the upload contained.

Neither Dominion nor KnowInk responded to a request for comment about Tuesday morning's problems.

Another key Georgia county — Fulton, which includes almost all of Atlanta — also had to delay processing absentee ballots after a pipe burst in a room where they were being counted.

Eric Geller contributed to this report.