contest in the central official tally, and unknown numbers were added to other contests in the central official tallies. The investigator found the same had happened in 2010. There were also votes lost by garbled transmissions, which the state election commission saw but did not report as an issue. 49 machines reported that their three internal memory counts disagreed, an average of 240 errors per machine, but the machines stayed in use, and the state evaluation did not report the issue, and there were other error codes and time stamp errors. In a 2017 York County, Pennsylvania, election, a programming error in a county's machines without VVPAT let voters vote more than once for the same candidate. Some candidates had filed as both Democrat and Republican, so they were listed twice in races where voters could select up to three candidates, so voters could select both instances of the same name. They recounted the DRE machines' electronic records of votes and found 2,904 pairs of double votes. In a 2011 Fairfield Township, New Jersey, election a programming error in a machine without a VVPAT gave two candidates low counts. They collected more affidavits by voters who voted for them than the computer tally gave them, so a judge ordered a new election which they won. A 2007 study for the Ohio Secretary of State reported on election software from ES&S, Premier and Hart. Besides the problems it found, it noted that all "election systems rely heavily on third party software that implement interfaces to the operating systems, local databases, and devices such as optical scanners... the construction and features of this software is unknown, and may contain undisclosed vulnerabilities such trojan horses or other malware." General issues Interpretation, in any counting method Election officials or optical scanners decide if a ballot is valid before tallying it. Reasons why it might not be valid include: more choices selected than allowed; incorrect voter signature or details on ballots received by mail, if allowed; lack of poll worker signatures, if required; forged ballot (wrong paper, printing or security features); stray marks which could identify who cast the ballot (to earn payments); and blank ballots, though these may be counted separately as abstentions. For paper ballots officials decide if the voter's intent is clear, since voters may mark lightly, or circle their choice, instead of marking as instructed. The ballot may be visible to