For LW 4, you will highly likely need a fresh Gnutella.net file which is a kind of connection cache that helps you to connect. You will find a reference to it & explanation how to replace the old one near bottom of page here
If LW 4 Will Not Connect (click on the blue link). (However, I've also supplied two fresh ones within zip files in the attachment below.)
LW must be CLOSED whilst you replace the old gnutella.net file !
