I am very newbie and i am still struggling with the basics:
I want to use a kind of “thank-you” template for possibly multiple subpages. And I am not able to make it work. It works when i put the folder on the base level of the content, but if iam making it a subfolder of another folder I am forwarded to the error page.
Not sure I understand the problem. Your danke page is a subfolder of mitglieder now and should be accessible in the browser via yourdomain.xyz/mitglieder/danke
Maybe you can provide more detailed information what exactly does not work?