I've had a terrible run of luck recently. Before two different shows, I've suddenly had a piece of hardware die on me.
The first one was a few weeks ago, my projector just wouldn't switch on. And I couldn't use any old projector as a replacement, it had to be a short throw with decent contrast ratio. Next, just two days ago, my laptop refused to login - this time just a few hours before the show was due to start. In both cases I had to cancel the show.