Symptoms

When we try to execute a report from SharePoint portal we are getting the next error:

An error has occurred trying to load the settings for the report. N/A:Could not load file or assembly 'Microsoft.ReportViewer.WebForms, Version=9.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. The system cannot find the file specified.
 

Diagnoses

The library referenced is part of the Microsoft Report Viewer redistributable package. We ensured that both the Microsoft Report Viewer Redistributable 2008 SP1 as well as Microsoft Report Viewer 2005 SP1 were installed.
 

Resolution

Once we resolved the missing dependency, the issue was resolved.