I just tried to re-vote in an ongoing election on https://vote.wikimedia.org and when I submitted my vote I got a blank page. Since I don't have access to WMF server logs I cannot tell what went wrong. The election is ongoing so immediate action is needed. I will mark this as high priority.
It might make sense for now to revert the SecurePoll on that server to the last working version (it worked fine until 9/19) while we figure out what went wrong.
We will also need a WMF server admin to look at the logs and tell us what the error message was. I don't know how to get their attention on Phabricator. I will send an email to wikitech-l just in case.