SOLUTION: Today I will now attempt the Amazon (not from the Play Store!) To install APP. Lo and behold, it works! Why am I merely did not come more this idea? The Watch Ever APP uninstall (PlayStore) and reinstall APP Amazon. Then it works again! Hope it works for you too ;-)
I think it could be important not automatically carry out the updates on the Kindle Fire HD 7, because if the app is also updated at Amazon, it could be that the APP then no longer work properly .... because it is then no longer compatible ?!