If you make any changes to the "MSG Fades" folder while this application is running (like adding, deleting, or renaming any of the fade modules), choose “Rescan for fade modules” under the “Options” menu.  This will rebuild the lists of currently available and currently disabled fades, taking into account the changes you’ve just made to the "MSG Fades" folder.

If you never make any changes to the "MSG Fades" folder while this application is running, you will never have to use this option.