7zip command line - cannot find code that works with archives

We are in the process of a server move, both to a new host and from a Server 2k8 box to a Server 2012 box. The server in question has a few drives that hold our sites and some utilities. These drives were duplicated exactly during the move. Data, folder structures, and permissions should all be identical.

Recently, when running a Jenkins task on this server, I found the following in the log:

G:\Websites\PathToWebsite>G:\Jenkins\Tools\7z a -tzip Website_PROD_Backup_20140311_.zip

7-Zip [64] 9.20 Copyright (c) 1999-2010 Igor Pavlov 2010-11-18

Error: 7-Zip cannot find the code that works with archives.

7-Zip is installed on the server and I can do the actions it's trying to do from the GUI. I'm a developer and am not used to troubleshooting something like this, and Google for the specific error hasn't led me to any resolution.

The closest match I could find is a site that says the command-line tool needs a few .dll files if it's less than 150K. I found the tool at the referenced path above and it was over 150K. I copied the .dll files from the install directory to that directory anyway. This did not fix the issue.

What should I do to fix this? I really need 7-Zip to work from the command line or significant parts of our build/deploy process will have to be done by hand.

Make sure you have the 7-zip command line version installed; it's separate from the GUI. YOu can download it here:

http://www.7-zip.org/download.html

Another reason for this error is when you have 7z.exe but do not also have 7z.dll - both are needed for the commandline program to work properly. Copying just these two files from the normal 7-zip GUI install folder is enough for a portable version of the commandline program on our CI.