>>I have a very good class to zip and unzip files which uses the WinZip command line utility. I didn't have the time to look at it yet but I thought I would share it at first just to see if someone has encountered that situation. Recently, a client has constructed zip files which are corrupted. Basically, even when using the WinZip interface, we can see that WinZip is crashing on such a file as the CRC is not valid. So, this makes the WinZip command line utility to crash as well. However, this WinZip command line utility is built so we can use it inside a .NET application. Not very easy to trap I could say, but as I said, I didn't have time to take a closer look at it yet. Has anyone faced that situation before and if yes, did you find an easy approach to negotiate with it?
>
>Maybe the base problem is that one or more files you're trying to zip are corrupted on-disk, so that causes problems with WinZip. If that's the case, you could experiment with trying to read the source file(s) before zipping them.
>
>Along the same lines, another possibility is that files are in use by other users or processes when you try to zip them.

Haven't used it but it looks as if Winzip isn't helping too much on errors: http://kb.winzip.com/kb/entry/168/

Have you looked at the new ZipArchive class in Net 4.5 : http://msdn.microsoft.com/en-us/library/system.io.compression.ziparchive(v=vs.110)