Last minute we were informed we had to change apartment because the bathroom door lock had been broken, I received a message only a few minutes before the check in time and I didn't check my phone in those minutes so we had already arrived at the apartment when we learned the news. Thankfully the apartment we were given instead was very close and it was gorgeous. We found it difficult to get into the new apartment since we didn't receive the email with the check in instructions, anyway we rang the reception and they solved our problem instantly. It all worked out for the best in the end. We found that the messages on Airbnb to the host were not effective, the reception on the other hand was very efficient and helpful, so just ring them.