If, when launching SuperCard for the first time and entering your name and registration number results in SuperCard quitting, it is most likely due to SuperCard not being installed correctly.
SuperCard requires two folders to be installed:
1.) The "SuperCard 4.73" folder should be placed in "/Applications" (the Applications folder on your startup drive).
2.) The "SuperCard 4.7.3" folder MUST be copied to "/Library/Application Support" (this is in the "Library" folder at the root level of your drive and not the one in your home/user folder).
Your downloaded "disk image" contains a window with aliases (symbolic links) to the correct folders at the right of the arrow symbols next to each of the folder icons. In icon view, dragging the folders on the left to the folders on the right will ensure the folders are copied to the correct locations.
A -61 is an MacOS permissions error and it is most likely the case that SuperCard (as currently installed) does not have write permission to all of the files it needs. You should "get Info" on the SuperCard folder in "/Library/Application Support/" and check the permissions. They should be set to read/write at all levels. If not, change the settings manually.
Regardless of whether you changed the settings, you should then apply the changes to all enclosed items using the popup or button (depending on what version of OS X you're using).