Can you tell me exactly the error that comes up when you're trying to see a CG with the MC in it? What is the name of the missing file?
As for getting the other ending, you don't need to reload, you basically re-did the innocent ending twice. Remember, Tailor Tales runs on a single save file. Once you've completed an ending, it should have automatically asked you if you wanted to go back to chapter 25 (where the route splits) to start the other ending.
So yeah, if you go to Settings > Character > pick whichever > Story > click on chapter 25 and select start new route. The chapter will ask you if you want to play the Passionate or Innocent ending, so pick which one you want :)