I bug is making me unable to use the hammer editor.

[A.I. the Artificial Idiot]

So I downloaded the "Ultimate Mapping Resource Pack" as I am new to mapping and wanted a sort of jumping-off point (And a tutorial told me to) but now when I click on my hammer editor desktop shortcut to says I don't have the file or something and the other connected files are in a weird file type or something. What should I do to fix this?