Minecraft PE crashes when starting with Lumia 550

Hi,
when starting Minecraft PE (current Version) for Windows 10 Mobile (current Version) on my Lumia 550 it appears only the "Mojang" logo then the app crashes. This Problem persists since several weeks!
I tried with:

• moving the app from SD-Card to phone memory - still not working
• deinstalling and reinstalling app - still not working

It seams that all purchased additions (via Microsoft Store) to Minecraft are lost, is that right or are they saved in XBox-account?
Can you please help me how to get this app working again?