Just to be sure, are you saying that the links on this page aren't working in German? Have you tried opening other websites to ensure that your Internet connection doesn't havre issues?
These do not work ("Hilfe" and "Feedback"-Links). I do not know if this error appears in other languages.
If you can, can you try checking with another XD user if they are facing the same issue?
Also, can you try opening this page? Prototypen in XD
For Feedback, the link is Adobe XD: Feature Requests: 03 : Sharing on the web (153 ideas) – Adobe XD Feedback : Feature Reques...
I am not sure if there is a separate link in German for the second.
Let me know if you need more info or assistance.