Voting problems

Several of my users has problems with voting i chritmas calendar

I get 1-2 messages every day similar to this:
"Door 16 can be opened, but when I press enter to respond, nothing happens. In other words, I can't participate. What's wrong?"

»Door x can be opened« is not part of our system. I think you are talking of a custom mail? To check the calendar I need the admin link. Please send it to support@pollunit.com (do not share it in the public forum). You can also forward the nonworking email.