German umlauts / papercss / Hugo

[jmooring]

Exactly. The file is not encoded properly. You should see:

text/plain; charset=utf-8

I suspect the problem in your convoluted workflow is caused by Notepad. Try an editor such as Notepad++, but make sure you change the default encoding to UTF-8 in the preferences.

I refer you back to my response to your original post:

Strange behaviour or my mistake?

If you have not already done so, I strongly encourage you to install Hugo locally, configure it, and learn how everything works. You can certainly install Hugo on a server, but it would be better if you could work out the kinks in an environment that you can control.