Just redownload the file, that happens when the file gets corrupted, it happens a bit.

With the firebox root thing, it is fine to keep the file in MyDocs, although you can't extract inside mydocs, which is fine because it is extracted into the theme folder.

Fun fact, the green was actually a mistake, I copied the theme from my theme folder and had green patched. Now I think each release will have a different colour just to make things interesting