4.8.1 behaves quite differently to the newer versions. You should delete your LW Preferences folder whilst LW is closed; instructions here: Point #2 & 3 in Fixes for Limewire (sample image included at bottom of page.) Your Preferences folder will either be called .limewire or limewire depending on whether you have deleted prefs folder since using new versions or not. So check the instructions carefully. LW 4.8.1 will not behave at all well with the 4.12 preferences.

Depending on what firewalls you have, you may need to delete the previous LW listing in the firewall setting & re-do it with LW 4.8.1 ___ Did you configure your firewall so it allows LW full access (advisable not to have 2 active firewalls b/c they can interfere with each other); Firewall configuration instructions (click on link)

If this doesn't help you then please answer with responses to this: System details - help us to help you (click on blue link)