[[!FileDownload? &getDir=`Support Library/product` &directLink=`1` &browseDirectories=`1`]]
&getDir=`[[++assets_path]]Support Library/product`
&getDir=`[[++base_path]]Support Library/product`
for &getDir, try to use absolute path, eg:
&getDir=`[[++assets_path]]Support Library/product`
or
&getDir=`[[++base_path]]Support Library/product`