Q: iMatch Crash

Appears that song or file # 19682 is corrupt or has a bad file name. Possible issues are special characters or uncommon symbols. Remove this file and try again. My iCloud match took about 15 hours for less than 2500 song titles which were 80% store bought albums, 19% itunes purchases and 1% obscure internet downloads. 

I recently activated iTunes Mach in iTunes 11.0.5. I recall the process uploading in alphabetical order of artist. I would work backwards from your last file under artist by album ascending order. Counting back from 19864 to 19682. It's worth a shoot. Good luck.