Cannot replace file contents

Hello, Using Windows 10 and the latest version, replacing the contents of a file isn’t actually replacing it. It’s my friend that has the issue. Replacing a savegame.dat that’s in a Minecraft 360 world and the savegame doesn’t actually replace. Yes he’s saving and resigning but even extracting immediately after replacing, the savegame is the same.

We had to downgrade versions and then use a completely different bin file. If we kept using the newest version to replace over and over, eventually it would throw errors and the bin would be corrupted. Please look into this issue.