It sounds to me like the package may not actually be downloading correctly to the Mac when the policy runs. Or its being corrupted as it downloads. I've seen that happen in some cases with Office installers.
Have you or can you verify that the installer makes it to the Mac when the policy runs? You may have an issue with whatever protocol is being used to deploy this, or something up with the CasperShare.

Also, is this the only install policy that fails like this?

I think the package is making it to the Mac when the policy runs. Here's more of the output from manually running the policy:

verbose: Checking for an existing instance of this application...

Checking for policy ID 65...

 verbose: Checking for active connection on interface "Ethernet"...

 verbose: Found active connection on "Ethernet"...

Gathering Policy Information from https://jss.mydomain.com:8443//...

 verbose: The Management Framework Settings are up to date.

 verbose: Found 1 matching policies.

 verbose: Removing any cached policies for this trigger.

 verbose: Parsing servers...

 verbose: Parsing Policy Install Office 2011 14 Installer. (65)...

Executing Policy Install Office 2011 14 Installer....

    Mounting afp://myserver.com/CasperShare to /Volumes/CasperShare...

 verbose: Result of mount attempt: 

 verbose: Result code of mount attempt: 0

 verbose: Starting Install...

 verbose: Determining Pacakge Type...

 verbose: Installing an Apple Package...

    Copying Office 2011 14 Installer.mpkg...

    Installing Office 2011 14 Installer.mpkg...

    Installation failed. The installer reported: installer: Error the package path specified was invalid: '/Library/Application Support/JAMF/Downloads/Office 2011 14 Installer.mpkg'.

 verbose: Removing local copy...

    Unmounting file server...

    Running Recon...

I'm not quite sure how else to tell if the package makes it to the Mac.

Also, this is the only installer policy i have at the moment. I am in a testing phase. I have other policies in place that seem to be working.

I think i fixed the problem somehow. I redownloaded our ISO for Office 2011 off our server and uploaded the Office Installer.mpkg from there to Casper Admin and reran the policy on the VM. It installed successfully.

But, were the logs reporting an incorrect error? Why would the package path become invalid?

I never got to respond, but my next suggestion was going to be to test if the installer you had would work when installed manually. its possible the pkg you had became corrupted in some way. As I said, I've seen it happen to Office installers. I don't know why they seem more susceptible to that than other installer pkgs.

As for the error, if the pkg itself was invalid, that's why it would report an invalid path, meaning the installer pkg it was trying to use couldn't actually be installed. yeah, I know its not the clearest error, but that's how it reports that kind of stuff.

Glad you got it working.

I get this frequently when I try to push Office after teh fact... however, if I log into the box and run the same installer manually it's fine. (I have a policy that dumps the office oem package and then runs the installer).