Excel DDE link to trading software

With the firewall running, when I try to update live DDE links in a spreadsheet, Excel freezes and has to be force quit. If I turn off the firewall, it updates fine. I can then turn on the firewall and it continues to get quotes just fine.

There are no messages from the firewall asking me if I want to allow the connection. How do I fix this so the DDE links are not blocked silently?

You could try removing any entries for Excel in Defense+ and firewall rules and putting Defense+ and Firewall into learning mode. Then use excel as normal for a while before changing the security levels back to their previous settings.