I don't have an "almighty coding attitude" (whatever that is) and I've never claimed I was a coder or that I know ruby that good. At best, I'm a beginner when it comes to ruby although I dare to say that I understand quite a lot of it since the base logic is the same/(almost the same) in every programming language.
This error has nothing to do with "folder depth/long path" since it never happens to me or anyone else (to my knowledge) that listens and uses Locale Emulator set on Japan or set their own windows locale to Japan.
The folder structure is the same for everyone but it only happens to certain people and the one thing everyone that complained about that problem in this thread has is that they don't use Japanese locale. This game was made in a Japanese version of RPG Maker and some of the scripts(only a few) actually use Japanese characters inside them for comparison or to call another function. Because the game isn't run in Japanese, the engine can't "understand" Japanese characters, and the file that in his case in located inside the folder, the game engine returns an error that it can't find it. To a user/player, it looks the same but the engine interprets it differently. To the engine, the file name and the name of the file it's looking for is not equal and it returns the error that it can't find the file even though the file the engine is looking for is inside the right folder and it's named correctly.
Maybe just installing the support for Japanese characters inside the windows instead of changing the whole locale to Japanese would also fix the problem but I can't test that since my PC is already set to Japanese locale and I've downloaded and installed all the files for the support of Japanese characters.
EDIT: To further illustrate what the problem actually is if you don't understand from reading the text is this:
On the left side is how the engine sees Japanese characters if you don't have your locale set to Japan and on the right is the same windows that shows how the engine sees the Japanese text with support. On the bottom are the files inside the folder and you can see how they're actually named.
In first case, where you don't have support for Japanese characters, the engine tries to find a file with that "Gibbrish" but it can't find it and returns the error.
In second case, where you have support for Japanese characters, the engine find the file and runs correctly.
So, everyone, keep telling people to not use locale set to Japanese and keep telling them to just change inside game.ini to 104E when they don't have text in-game. That will really help them in the long run.
Changing the file names to something else that doesn't have Japanese characters would fix the problem but would require finding on every map, on every event tab that calls those pictures with Japanese names and change them manually to call renamed versions of the picture. This is something, I absolutely won't do. It is time consuming and I would probably never find all the events.
I thought telling people to simply change their locale or just use locale emulator would be enough but I guess it isn't.
I hope with this, this whole issue is now solved and people just simply listen and do what they're told.