Licensing scheme in version 6.0+ was completely changed. Valid license keys from versions < 6.0 are NOT COMPATIBLE. Please contact firstname.lastname@example.org to convert your valid license key into new format free of charge.
Perform non planned upgrades only if you are having serious issues with your current version of the product or you are told to do so by the Support Team. In all other cases continue using your current version and plan routine upgrade at a later date. Beware upgrade process is error prone and fragile due to the complexity of the application and a lot of integration points with Squid and OS so it does not always go smoothly. Backup before upgrading!
In order to upgrade your current installation of Web Safety ICAP Server to version 6.1 follow these steps.