OK, try this then:
$ cp ~/.cache/upstart/unity8.log.1.gz ~/Documenti/ $ sudo zcat /var/log/lightdm/unity-system-compositor.log.1.gz > ~/Documents/unity-system-compositor.log
OK, try this then:
$ cp ~/.cache/ upstart/ unity8. log.1.gz ~/Documenti/ lightdm/ unity-system- compositor. log.1.gz > ~/Documents/ unity-system- compositor. log
$ sudo zcat /var/log/