Thanks a lot for your answer even if I got that error the plug-in was installed and now it's working. Do you suggest to uninstall it, correct the source file and then reinstall it?
I'd be really surprised if the back end is actually functioning correctly with an error like that. I could be wrong, so please someone correct me. But if it were me personally, I'd uninstall the plug-in, correct sources, apt update then install again. You shouldn't get an error at all. Or rather, let me put it another way - whenever I've had an error like that things never worked as they were supposed to.
Actually, if memory serves, it's specifically backports contrib you need - but if you add contrib to everything you have it won't hurt.
Can you actually do a:
from the terminal and see your tank? (assuming it's imported).
You should get something like this:
If you don't, it's not working.
Edit: That error appears to show that the kernel module failed to build, so I don't see how it could be working.