Can't Load EXS24 Instruments ("Missing Files")

Hello, This is my first post since I am new to the forum and this is the reason why I registered.

I have a problem when I load an Instrument in Garageband, Mainstage, or Logic. A lot of them are bass instruments. Such as when I click to use

"Subby Bass", I get something like:

"Can not load EXS24 Instrument. Missing file "IL P-bass bomb 21.aif" could not be found" and other ones, too, but the main one I want to use is Subby Bass.

I checked in the Sampler Files folder(s) and under that instrument, and there were no files; it was empty.

So I tried going in to Mainstage and redownloading the Additional Content - Remix Tools, Rythym Section, and Logic Essential and Additional Content. I redownloaded a few times in fact, and one or two of them were interrupted. Still, the files aren't there.

This problem is driving me insane. and I can't find any other solution on the internet, whatsoever. All of the software are the latest version and I am running on Mac OS X 10.7.2.

If anyone can help, that'd be greatly appreciated.

Thanks,

-Clayton