I have had an issue with the HDMI adapter that came with my Magpi Subscription as part of the free gift. The adapter doesn't plug all the way in as the chunky plastic bit is bigger than the hole in the case meaning the adapter doesn't plug all the way in! In the past the slightest knock by touching the cable would cause the screen to go pink or something like that but today it just wouldn't go in! I spent a few minutes trying to figure out why my pi booted but nothing came up on the screen for it to be something this simple! It is all fun learning about computers when issues like this come up, however, this could be a common fault and I feel as if it could easily have been prevented by a different adapter being given as a free gift in the future. I simply solved this by taking the Pi Zero W out of the case.
By the way by Pi was properly in the case and it was the official Pi Zero case.