I rip a CD, and when it's all done, my library remains empty.

I tell it to search for new music.  I point it to the place where I store
all my ripped music (a share on a NAS), and it says that it found hundreds of
files, but added 0 (as if it already has all of them in the library).

When I try to add an individual file (File menu --> Add to Library --> Add
file
I get the notorious error C00D11CD.