I tried to start after extracting the past season and making a new roster, but it doesn't work. Is there a place that can help me create a custom file?

I am not exactly sure what you are referring to and what is not working so if you could go to our webpage, click support at the top and open a ticket that would be great. Please include in the ticket any error messages you are getting and whatever the new roster file is you made and we can check it out

Before that, do you have a manual for creating a custom file?

There is not a manual for creating a custom file - you can look and see what the default files are for image size and make sure you stay within those parameters for your custom images