I recently ran into the same issue after upgrading our AD infrastructure from a 2003 to 2008 domain. There is a reg entry in the Default Domain Controllers GPO here:
Computer Configuration>Administrative Templates>System>Net Logon>Sysvol share compatibility
If you set "Sysvol share compatibility" to Enabled, everything will start working again.
> On Wednesday, September 08, 2010 12:18 PM Jason Chambers wrote:
> Hi All,
>
> I am having a really strange issue where I have an MSI package of
> Office Communicator on a folder SYSVOL so that it can be office
> deployed. I run a mix of Windows 2008 R2 servers and Windows 2003
> servers, all Standard Edition. I can run the application without
> issue, except that Windows XP machines gets the following error:
>
> "This installation package could not be opened. Verify that the
> package exists and that you can access it, or contact the application
> vendor to verify that this is a valid Windows Installer package."
>
> If I copy the package to the desktop, it works. If I run the package
> through a SYSVOL of a Windows 2003 DC, it works. I can run exe's and
> vbscripts from the Windows 2008 R2 DC's without issues, but this pesky
> MSI is giving me grief on all Windows 2008 R2 DC's only.
>
> It seems like Windows 2008 R2 does not like to allow execution of MSI
> files from its share for local installation. Is there isomething that I
> am missing?
> Submitted via EggHeadCafe
> ASP.NET 4.0 browser capabilities
> http://www.eggheadcafe.com/tutorials...abilities.aspx