If you're having trouble accessing the complete roster, there are two things you can try:
- Check your General Settings, in the Options menu. The roster settings can be toggled between the new grouped layout, the 12-character beginner roster, and the classic all-fighter roster. Change that setting to suit your needs.
- On either of the complete rosters, the button you have assigned to start and pause the game will flip through each page, one after another, and go back to page 1 at the end of the list.