IRC client cannot connect on Windows 10

Question

When trying to launch an IRC client on my Windows 10 laptop, I get the following error:

* Looking up irc.freenode.net
* Connecting to irc.freenode.net (31.13.222.109) port 6667...
* Connection failed. Error: An attempt was made to access a socket in a way forbidden by its access permissions

This happens with both XChat and an IRC client I tried that's a Chrome extension.

Checking my Firewall settings indicates XChat is an allowed app.

I've also tried disabling the firewall entirely.

What else should I be looking at?

Answer 1

After much further hunting, and with a colleague's assistance, discovered that McAfee AV is blocking IRC on my computer as a "suspicious activity", according to its logs.