You should start completely over. Delete the FatBomb files and reupload them.
Often, mistakes will occur on the 3-4-5th installs because we think we know what to do, but will forget something.
As you posted, you know the script works on a subdomain on your host. That means the scripts are OK and the host is OK. That only leaves one thing: User error.
Start over from the begininng reading the ReadMe and viewing the video, assume you know nothing. If you download Fatty from a domain of your's, do it a couple of times to make sure everything was downloaded. Then, when you reupload, do that a few times just to make sure.