Make sure you are entering your account name, not one of your grouped nicks. (You need a registered account, for this to work).
SALS authentication successful!Coulple of things that I was doing wrong. First I needed to register my nickname with NickServ through
Freenode Web Client. Second, I placed the downloaded files in the wrong mIRC directories. Thanks to your link I found the
/run . command which opens the right directoty for the sasl.mrc and SASL.dll files.
Thanks a million for your help.