Rocksmith Toolkit Error when generating song

[AwkwardToast]

So I just started learning how to make my own custom songs and the whole process went relatively smoothly until I went to generate my song. I was met with an error that says:

Application.ThreadException:

Value cannot be null.

Parameter name: path.

Here's my log file as well.

Any help is greatly appreciated! 

_RSToolkit_2020-12-04.log