Can't Select Exs Files In Exs24 Instrument Editor Options

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.