Its clear that paths are not set right.
Did you try an uninstall / reinstall of onkyo?
no, I didn’t, but it was actually a clean basic installation with a clean installation of the script with this lines
but i will set up a completely new system with pimtaic for testing
sudo apt install python3-pip
pip3 install https://github.com/miracle2k/onkyo-eiscp/tarball/master