Plugin Install failed….. Developer

Hi!

Can someone look into my subversion repository at http://plugins.svn.ww.wp.xz.cn/wpzon/ what may be wrong, because when i want to install it on the blog it gives this error message The package could not be installed. No valid plugins were found.
Plugin install failed.

Plugin: http://ww.wp.xz.cn/support/plugin/wpzon
Thank you!