If you want to put a file back into the game, you NEED the Header. The game checks if the header is correct.

If the header is not correct, the game can't display it...

Summary: You NEED the correct header. If the header is wrong, the game can't display it. Usually, the default settings will work fine for 99 of 100 games. So, please try the default setting first. If it doesn't work, then you can search for the correct header settings.

You find them here: "Game Directory"/www/js/rpg_core.js Search for "function Decrypter()"; there, you can find all values.