Go to the Settings -- Configuration screen.  Look for the checkbox that reads "Disable Conns Grid."  If this box is checked, remove the check-mark, stop and restart SpamFilter.  Barring any other unknown issues, the connections grid should start working for you.

Once you've verified that it works, however, you might want to disable it again unless/until you really need it.

The connections grid has been a part of SpamFilter ever since I became a customer of this fine product, but the "Disable Conns Grid" option was added later at another customer's request.  By disabling this grid when it is not being used, system resources are freed and SpamFilter performance is improved.  Many users enable the connections grid only when they need it for a specific troubleshooting issue... a mail session that hangs, or something like that.  This screen, combined with other SpamFilter utilities such as the debug screen, can be used alongside OS utilities such as Netstat for troubleshooting purposes when needed.