I think I figured it out! I tested my instructions on a VM running a bare-boned version of Windows 10 and got the same error you did. The issue is some systems don't play well with PyTorch's Cuda edition (which is the one I linked). Also, many people have various encoders already installed that play well with Python and some don't (especially if we're dealing with someone who's installing this on a fresh version of Windows), so I was getting SoundFile errors too. Installing soundfile fixed that issue though! Please remember to install and configure ffmpeg before trying to run mp3, mp4, m4a, and flac files through this tool!
Leave your installation as is and simply install the following and you should be good. Please let me know if this works for you! I also updated the main thread with these instructions. One thing though, don't check the GPU option is you don't have a stand-alone one installed.
pip install torch==1.5.0+cpu torchvision==0.6.0+cpu -f https://download.pytorch.org/whl/torch_stable.html
pip install SoundFile