Cannot unzip or install Network Theme download

hi gang, I think this is a new issue. I cannot seem to download a "unzipable/installable" package from your site for Network theme. I am using a Mac, but usually have zero problems. Also, when I try to install the package through the Wordpress dashboard, I get this message:

Installing Theme from uploaded file: 11531_network-theme-1.5.2.zip

Unpacking the package…

Incompatible Archive. PCLZIP_ERR_BAD_FORMAT (-10) : Unable to find End of Central Dir Record signature

Any help is much appreicated,

Glad the world is still here,
Tim