On a Mac, if you are using a Java version lower than Java 7 update 45 then the following Java version update popup window appears in Safari or Firefox:

If you click Later/Block then the following message appears when you scan the device:

The following steps show how to install latest version of Java:

1. Click Update to be redirected to the URL to download Java. If you had previously cancelled the update, visit http://www.java.com/en/download/help/mac_java_update.xml for instructions on updating Java on your Mac.

2. Download the jre-7u45-macosx-x64.dmg file, or the latest Java version offered.
3. Review and agree to the terms of the license agreement before downloading the file.
4. Double-click the .dmg file to launch it.
5. Double-click the package icon to launch install Wizard.

6. The Install Wizard displays the Welcome to Java 7 installation screen. Click Continue.

7. On Standard Install on Macintosh HD, click Install.
8. After the installation is complete, a confirmation screen appears. Click Close to finish the installation process.

9. After the installation is complete Java application will be re-launched.
10. Under System Preferences click the Java icon to launch the Java Control Panel.
11. Go to the Java tab in Java Control Panel and check whether you have the latest java version installed.
12. Now login to https://ciscoactiveadvisor.com/ and launch scanner and check whether you can perform the scanning process. In case of issues, restart the system and retry.