Downloading

I have moved the file placement after i down load a file. I am trying to keep my music more organized, and now with some files I get a Could not move to Library sing thing after i download a file. does any one kno why this is happening. I know how to fix it( go to the incomplete folder outside of limewire, and I just move it to the shared file) but i still don't kno y this happens. can anyone please help me??