Hello all,
I was able to solve the problem. Once again it was totally simple. At work I only work with Docker on Linux. At home I just wanted to try it out quickly on Windows. Well, that was the problem ... again ...
For all of you who might have this problem, you have to change the "start.sh" file back to UNIX format on Windows. If you have installed e.g. Git Bash you can do this with "$ dos2unix.exe start.sh".
After that you can install the image without any problems. Thanks a lot for your help. Your answers at least showed me that the problem must be on my side.
Shows again why it is better to do the stuff on Linux directly.
Thanks again