When installing the Kerio Control VPN client for macOS on Big Sur (11.0), the below error message is seen on the Installation step:
The software to be installed required Mac OS Mountain Lion 10.8 or newer, which is not
available on this computer. Please use an older version of Kerio Control VPN client or
upgrade your Mac.
macOS Big Sur support was introduced in Kerio Control starting with version 9.3.6. Please download and install the latest version of Kerio Control to successfully install it on macOS Big Sur.