What version of Java are you using? Have you tried updating Java at all? The latest update is here. Use the JRE offline installer & remove other Java installed before installing the latest.
Java SE Downloads

Deleting the preferences folder is often a fix for weird issues & at any rate, it won't hurt anything. Deleting the folder will reset LW's options to default, so you'll need to go back through LW's tools > options & reset things when you restart LW.

Make sure LW's properly closed before deleting the prefs folder. If you've used much older versions of LW in the past, also look for a folder in the old location of C:\Documents and Settings\your username\.limewire

*If you delete the prefs folder & find that you can't connect afterwards, see the thread below for info about replacing the gnutella.net file & other connection fixes*
If LW Will Not Connect

You could resintall using the offline installer if you like but before that, try the latest Beta version. You can download the Beta from your Pro download page (if you use Pro) or from the usual basic download page.

If you think it's a version related issue (saw your other thread), revert back to an older version of LW. Do you still have a 4.14 installer saved? If not, this is a link to a hosted 4.14.8 basic installer.
LW Basic 4.14.8.exe

If you install the old version & the firewall icon goes away, you could post in the Bugs & Beta Testing section of this other forum. The developers might see your post there.
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Otherwise, maybe there's a router issue. Have you tried port forwarding? The instructions for your router are here.
Port Forwarding for the Dlink DIR-655
Don't forget to set up a static IP address first. LW's listening port, port in the 'manual port forward' box & port forwarded within router setup should all be the same number.