Could not load file or assembly Microsoft.ReportViewer.WebForms, Version=8.0.0.0

James Morris — Fri, 02 Sep 2011 15:04:33 +0000

We’re starting to run RSinteract against SQL Server Denali and have hit an issue with the Report Viewer control, this solution could also apply to earlier versions of SQL Server…

When running RSinteract for the first time on a SQL Server 2008, 2008 R2 or Denali machine you may come across the following error:

Configuration Error

Description: An error occurred during the processing of a configuration file required to service this request. Please review the specific error details below and modify your configuration file appropriately.

Parser Error Message: Could not load file or assembly ‘Microsoft.ReportViewer.WebForms, Version=8.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a’ or one of its dependencies. The system cannot find the file specified.

Source Error:

Line 26:

Line 27:

Line 28:

Line 29:

Line 30:

Source File: C:\Program Files\ICS\RSinteract\Website\web.config Line: 28

Assembly Load Trace: The following information can be helpful to determine why the assembly ‘Microsoft.ReportViewer.WebForms, Version=8.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a’ could not be loaded.

This is because RSinteract is trying to run the SQL 2005 Report Viewer Control. You can download it here:

http://www.microsoft.com/download/en/details.aspx?displaylang=en&id=4016

Unable to load client print control

RSinteract — Fri, 05 Dec 2008 15:40:44 +0000

UPDATE: Further information on alternative fixes has come to my attention via StackOverflow.

This new error has popped up since Microsoft released the update KB956391.

The update is for a vulnerability in the GDI+ DLL which allowed a malicious user to execute code on the client machine (good old! – ed). The fix uses ActiveX Killbits which is a setting that Internet Explorer checks for each ActiveX control. If the Killbits are set, IE refuses to load the control.

The update set the Killbits for the version of the RS Client Print ActiveX control which is used by the version 8.0.0.0 of the ReportViewer which is referenced by RSinteract (and Report Manager). Thus the printing will not work in either.

To fix Report Manager you need to apply the ReportViewer SP1 patch and the Security Update for SQL Server SP2 (KB954606). Once this is working again you can fix RSinteract.

To fix RSinteract you need to apply another Security Update for SQL Server SP2 (KB954607).

Let us know if this fix doesn’t work for you.

RSinteract Development Blog » reportviewer

Could not load file or assembly Microsoft.ReportViewer.WebForms, Version=8.0.0.0

Unable to load client print control