When you have a windows user, which uses special letters in their username (in my case: "å", but I have seen other users with "!" in their username having the same issue), upon launching the game (not the launcher), you will get errors:
"Error: Could not find java.dll"
and
"Error: Could not find Java SE Runtime Environment."
errors.

I have been able to run minecraft on this user before, while it was not a Windows Store App exclusively. After I was forced to download the app to continue playing, I am no longer able to launch to application. I created a user without special letters, which can launch the game without errors.