Gee whiz. Your question has been answered and answered and answered. GM runs inside a SANDBOX. What this means is that you do not have access to all the folders on the drive. You ONLY HAVE ACCES TO the %localappdata%\<Game Name> directory. That's it. Ain't no way of getting around it WITHOUT USING AN EXTENSION. Your E:\Test folder is quite obviously not inside the %localappdata%\<Game Name> directory so you DO NOT HAVE ACCESS TO IT. That is, unless you use an extension, which has been mentioned multiple times already. (This is specifically for windows, other platforms will have another specific place in the drive that you have access to, but the exact same scenario applies).