i talk the most time with me 🙂 but it is also for other user
now i got the install without errormessage and install the stable firmware is possible. plugin i dont try further until a new stable firmware will arrive.
after
sudo apt-get install duetsoftwareframework
i modifeyed the config.json to the correct gpio pins. than i deinstalled it again, reboot and installed it again and now....all fine also with installing the stable firmware. plugins i dont have tried because also with the raspberry and manuel installing like in the guide it was not possible (and all needed services was running also appamor) in standalone it tried it with the latest beta and all was fine