So I read from an official source that if you used an action replay cheat to walk through walls to get to where route 10 used to be, it would just be trees. So I did it and got just trees. Then, I put the game down and came back to it the next day and what I saw was insane. Route 10 appeared perfectly. What happened here?
Nothing's wrong.
>However, if the game is reverse-engineered, the entire route is accessible, minus scripts, wild Pokémon data and buildings (as seen here). In both areas, Route 6's theme plays instead of the regular Route 10 theme.
Unova Route 10
I'd probably have to say that your game may have just glitched up. I'm not 100% sure, but that's probably my best guess. It could've just been the lighting in the room. You may have just seen trees. I don't precisely know... But You know now that I think about it, your game could've just not been able to load the cheat code so quickly. Remember, I'm JUST GUESSING, but that's what I think is going on.
Or... You're Just Lying... :|