From: DeskNow Knowledge Base
http://www.desknow.com/kb/

I cannot extract/view a backup zipfile on Linux / Unix, using 'unzip'
http://www.desknow.com/kb/idx/9/096/article/

This article applies only to users of the 'unzip' utility for Linux / Unix.

Depending on what parameters were used for compiling unzip, it may not be able to open large zip files (> 2Gb). This is a known unzip bug. The error message is actually deceiving, because it will report a 'file not found' problem!

You can use a different utility like p7zip (http://p7zip.sourceforge.net) or a windows-based unzipper like WinRar.