SafeSquid ISO or SAB is a Net Install ISO which means it requires Proper Internet Connection to Install the Complete SafeSquid using ISO.
Many Files are downloaded from Internet during the Installation, one Such file [Preconfig File]
Please check that you have provided a proper internet connection and your network settings are proper means that which the IP configuration in the previous step you are able to connect to internet properly.
Note: Also if the Setup is done behind a Firewall or any Network Layer Security System make sure Internet Connectivity is provided.
Inorder to check Internet Connectivity during the SAfeSquid ISO Installation, you can switch to another Terminal using
ALT+F2 [Opens a New Terminal]
ALT+F3 [Opens a New Terminal]
ALT+F4 [Default displays all important logs which can be found in /var/log/syslog in the current running installation system]
You can got to any New Terminal [ALT+F2, ALT+F3] and can perform a PING to Google or anywhere on internet to check internet connectivity