EXS 24 Logic Sampler Users Group

I'm using Logic Platinum 6.3.1. I just installed the Xtreme Digital sample collection. 
When I try to open any of the .exs files installed in the Sampler Instruments folder for 
editing, they're all dimmed in the file browser window and can't be selected.

I also just installed the Xtreme Analog collection and those .exs files work fine.

I noticed that when looking at the file previews in the Finder browser, the Xtreme 
Digital exs files show up as a bunch of text characters. The Xtreme Analog exs files 
appear in the preview as an EXS24 document icon. Both of them are identified as 
EXS24 instrument files, though.

I've tried reinstalling twice but got the same results. I hope someone out there can 
help with this. Any help would be appreciated.