To see the log output from any of your completed scans, successful or not, head to Activity > Scan Logs in the application and you will see an interface that looks something like the following:
The scan logs interface is quite simple and very similar to the configuration alerts interface in the previous section. At the top is a keyword and identifier filter. Just like in the configuration alerts interface, click a scan log item in the list and you will get a modal containing the most recent log from that particular machine. You can then read through the log to glean any information that might be useful in understanding or debugging the scan for that machine.