Invalid number specified for 'slices-per-file'

[Trentflix]

I haven't changed the config options and am getting the titular error. I see you specify parpar master branch should be used. I used the default instructions for installation which states:

npm install -g @animetosho/parpar

Note that installing from NPM essentially compiles from source, so see issues listed in the following section if the install is failing on the build step.

Which is what I did but is there an alternate method I should be using?