Hi Jacob,
You may need to extract the downloaded folders twice to get the files in correct formats.
After downloading a dictionary at the websites we mentioned, you'll get a .tar.bz2 file. Then you need to extract it to get a .tar file. The last step is to extract the .tar file again. You'll see there're several files in it, and they're presented in the right formats (.dict.dz, .idx and .ifo).
Best regards,
BOOX Team