My app stops working on some devices

For one unknown reason my app stopps working on somlen devices. This is the link to my app: https://play.google.com/store/apps/details?id=appinventor.ai_clerckxjeroen.Ezemaal 

It works great on my device and some of my friends, but it is showing the message "App has stopped" when opening the app on some other devices.

Can someone please help because i do not know the problem.

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1. switch screens correctly

The recommended method of switching screens in App Inventor

2. follow these recommendations Using Images with App Inventor

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I tried your solution, but this did not worked out. I tried an other build of my app from april 2015. This version worked until february this year on every phone. Now it doesn't work at all. None of my previous apps are working when, i make a recent build. Can you please help me!

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