yesterday I updated my ice age village on my iPad. After doing this, my ice age village will not open. Why???

A question best asked of the app developer. However, have you tried to reboot your iPad? Hold down on the sleep and home keys, past when you see the red power down slider, and until you see the silver apple. Let it reboot and try again

Another thing to try is to quit that app and restart it. To do that, tap the home key twice, you'll see the apps all appear in a line at the bottom of the screen. Swipe if you need to to get to the icon for your app. Hold down on it until it starts to wiggle. YOu'll see a - in a red circle. Tap on that to close the app (you're not deleting it, just force closing it so it'll restart). Tap on the home key again to exit the mode and then try to open your app.

If neither of those fixes it, I'd take a look on the app developer's page in iTunes, see if others are also reporting the issue (things like this will show up in the feedback for the app almost immediately). If they're not having issues then you may need to contact the app developer and see what they say.

It sounds like the latest update the developer released has broken the app. Find that app in the App Store, go to the Reviews tab, and see if there are a lot of people on the latest version reporting the same problem. The developer likely needs to issue another update to fix this.