The majority of duplicate ballots for the upcoming June 6^th primary election were generated because voters themselves requested a second ballot – perhaps because they changed parties or changed their address.
But registrar of voters Jill Lavine says a few ballots were mailed out due to a problem with the voter computer system:
 
We’re not quite sure what happened, but a couple people that we got calls from said, “You didn’t do any changes to my voter record, why did I get a second ballot?”
 
Lavine says voting officials have flagged the affected ballots.  In the unlikely event an absentee voter does return two ballots, only the most recent one will be counted.