UWP, Windows App: Cannot add Files manually

Question

When I try to run the Windows Store App Certification Tests for my Project I always get the errors you can see on the following images.

These errors seem weird because they even occur in the main.min.js file which is empty and in the via Visual Studio included jQuery files.

In addition it also complains that all files I added manually are not UTF-8

How do I fix that?

Answer 1

I don't know why, but due to some reason Visual Studio created the files listed above in the wrong Encoding Format.

So I ended up resaving each of them with the UTF-8 Encoding Format.