s2gus24
Hello.
OpenATV 7.1 is only a beta version. I do not recommend using it at all. It is a version designed for developers and beta testers. Even OpenATV 7.0 RC1 is not official yet. Anyway, this is using Python 3 code, which my plugin already supports.
Your problem is, as you write, in the running or downloading of the 7-zip archiver.
First, the 7-zip archiver is searched on the Enigma2 feed-server.
Second, if it is not found, then a binary file (stand-alone) is downloaded from the github portal.
However, this is partly, still, unfortunately dependent on the Linux kernel and its system libraries + chipset architecture (mipsel / arm / aarch64). So I think the 7-zip archiver has downloaded to your receiver... but it's not working properly.
Please try to check whether it is downloaded or not:
find / -iname "7z*"
... and if it's downloaded, try to run it from the location where it was found, for example:
/usr/bin/7za --help
.... and / or:
/usr/bin/7z --help
Alternatively, you can enable the debugging in the OpenATV MENU, then restart Enigma2, and rhen the error occurs, send the created, latest, debug-log file into the discussion. There will be more info on what went wrong.
The second thing that is possible is that you are using a VPN and you have an incorrectly set up gateway to the Internet (via a VPN external server or via another machine in the VPN).
Thanks for report.