July 18, 2014

I deployed an asp.net application but when I ran the application, it failed with the message "Could not load file or assembly 'Microsoft.ReportViewer.WebForms, Version=, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. The system cannot find the file specified." . I re-checked the web.config file and it had the following line under assembly section

<add assembly="Microsoft.ReportViewer.WebForms, Version=, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A" />

What this means is that the application required ReportViewer which is not installed or probably the right version is not installed. The version number is specified in the setting as well and in this case we need version 10.

Different versions of the Report Viewer can be downloaded from the Microsoft download center.

Install the necessary version and then re-run the application fixed the issue.


Reference: Shahed Kazi at AspNetify.com