Unable to load client print control - Report Viewer Printing Error

The SQL Server Reporting Services Report Viewer control, found in Report Manager, SharePoint, and custom ASP.Net applications, utilizes a print control that contains a reference to a GDI library with a security vulnerability. Microsoft updated the vulnerable GDI library by deploying a new print control. Microsoft then sent out KB956391, which deployed a killbit that disables the old print control. The problem here is that if you haven't deployed the updated Report Viewer control to all your environments, then all your clients, who automatically received the killbit, are no longer able to print. They receive the "Unable to load client print control" error.

If you're in an enterprise environment where everyone is a limited user, you have secondary problem. Once the Report Viewer control is updated the client needs administrative privileges to install the updated ActiveX client print control. There have been reports of problems installing the updated ActiveX print control. I have experienced both successful and problematic manual installs. If your enterprise has the means to execute remote installations as an administrator, then you can simply take the contents of the RSClientPrint.cab file, copy them to the remote client, then remotely run a regserve32 on the RSClientPrint.dll file. You can find the updated RSClientPrint.cab file in the ReportServer\bin folder of your SP3 or KB954607 updated SSRS installation.

Microsoft recently issued additional guidance on this issue.

Additional Resources

MSDN Forum Post

Brian Hartman's excellent summary of the issue

Mariae's solution summary