Using the zip-file, it failed, too:
[tt]#> unzip modx-0.9.2.1.zip
Archive: modx-0.9.2.1.zip
End-of-central-directory signature not found. Either this file is not
a zipfile, or it constitutes one disk of a multi-part archive. In the
latter case the central directory and zipfile comment will be found on
the last disk(s) of this archive.
unzip: cannot find zipfile directory in one of modx-0.9.2.1.zip or
modx-0.9.2.1.zip.zip, and cannot find modx-0.9.2.1.zip.ZIP, period.
[/tt]
Tipp for Linux-Users:
Download the tar-archive and type
[tt]
#> gunzip modx-0.9.2.1.tar.gz
#> tar xvf modx-0.9.2.1.tar
[/tt]