Haha, don't mind the spoiler. It's an old game at this point. There are 3 branches. actually. The Rin/Koakuma ending, the Orange/Daiyousei ending, the Ruukoto/Reimu ending, and there's the true Reimu ending, which is the one I consider "canon" for this game. Though there was some comments made that the true ending violates Touhou lore because there was a cameo character from another franchise in it. My argument is that Gensokyo is where all things forgotten went and that character hasn't had any new project announced about her until pretty recently, so her winding up in Gensokyo should be possible.
Oh and there's also the default ending if you don't fulfill the requirement for any of the above.
That bug is known. Unfortunately, I can't pin down the cause (I'm not a programmer and it's solo project too), so sadly it'll always be there. My apologies. I do want to once again thank you once again for trying the game out however! Thanks!