Today I tried a few different tutorials how to install the Repetier-Server on a Raspberry Pi Zero W. It was quiet hard an no tutorial seemed to be up-to-date.
Then I found the simplest possible solution:
THE IMAGE DIRECTLY MADE FROM REPETIER:
Just download the image, use Win32DiskImager or the tool of your choice and follow the few instructions on that page. Thats it! Everything was working immediately.
Have a nice day!