Use latest Beta of 7zip from 7zip.org to uncompress
7zip could be downloaded from here
OS X Lion Server includes a host of enhancements that give you more control of your Mac server and the users who access it. The Server app — new in Lion Server — features a setup assistant that walks you through the server configuration process step by step. So now anyone can turn just about any Mac into a server. Profile Manager lets you remotely manage computers running Lion and iOS devices such as iPad and iPhone. You can even send updates to your users wirelessly via push notifications. Lion Server also adds file-sharing capabilities for iPad; includes improvements to Wiki Server, iCal Server, and Mail Server; and comes with Xsan built in.