You get this when the original host (computer) that listed the file as available is no longer available - it could be busy or it is no longer online. In any event the exact file requested is not there so Limewire is searching for an exact match to the original... keep in mind that other files may be out there with the same or near same content but they are not exact matches.... if you encounter this, the best resolution is to search again for another source and try it.... I have done this and found multiple variations and tried to download them all... once one starts to go I kill the rest.