https://phys.org/news/2018-11-midterm-voting-exposes-problem-aging.html

Scanners used to record ballots broke down in New York City. Voting machines stalled or stopped working in Detroit. Electronic poll books used to check in voters failed in Georgia. Machines failed to read ballots in Wake County, North Carolina, as officials blamed humidity and lengthy ballots.

Those problems followed a busy early voting period that revealed other concerns, including machines that altered voters' choices in Texas, North Carolina and Georgia.