I will upload for you the possible missing files, use the following Interface folder: https://www.sendspace.com/file/h8rtu0 (File size: 8 MB)
- You can extract / paste it in your "InfinityMU client/Data/" folder
But still some files might be missing from other client folders due that you haven't downloaded the client successfully at first place.
So you can just re-download the game using uTorrent software from here: click me