From CNN:

“We have received reports from Horry County that voters are being turned away from the polls, because electronic voting machines are not working and paper ballots are not available,” Buzz Jacobs, McCain’s South Carolina state director, said in a statement. “Some voters say they are being instructed to return at a later time. We are disturbed by these reports and hope that this issue is resolved immediately. We encourage any voters who were turned away from the polls to return again to their polling place this afternoon to exercise their constitutional right to vote.”