There is a chance this might have happened:
Downlds refuse to reload (click on link)
Else, you have accidentally deleted your files.
Accidental erasure of files from Library
It might be worth deleting 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 LW prefs might be corrupted.