you have to submit the feedback to let the AV upload a zip file with logs and your comments to our servers.
The logs are collected from various directories - all /tmp/avast*.log files, some avast config files, etc.
The support package zip file (as we call it) appears in /tmp/support_pkg before you send it.
However I just realized that the package might not be send because it look that the avast service is not running.
Could you collect them manually? Start "Terminal", then "cd /tmp", "zip LOGS avast*", and send me the LOGS.zip that will appear in /tmp directory, please.