Microsoft does not distribute the Common DLL in isolation. Instead, they provide a unified redistributable installer that includes all ReportViewer 9.0 components.

After installing the Microsoft Report Viewer 2015 Runtime, you can extract the Microsoft.ReportViewer.Common version 9.0.0.0 assembly from the installation directory. Typically, the assembly is located in the following directory:

If you are developing the project, open Visual Studio, select the assembly in your project references, and change the property to True .

Avoid DLL download websites that offer the standalone Microsoft.ReportViewer.Common.dll file. These are often outdated, unverified, or infected with malware. Always download from official Microsoft channels or trusted package managers.

A: No. ASP.NET Core requires modern ReportViewer controls (version 15.0+ with Microsoft.ReportingServices.ReportViewerControl.WebForms ).

Here is the long story — and the practical solution — regarding that specific version.

This occurs because:

When distributing a .NET application that relies on version 9.0.0.0, you have two main options to ensure the application runs successfully on client machines.

To get Microsoft.ReportViewer.Common version 9.0.0.0 , Download and install the official Microsoft Report Viewer Redistributable 2008 package. This is the safe, supported, and effective method that will resolve the assembly load errors for your older .NET applications.

Are you trying to an existing legacy application, or are you developing a new report in a modern version of Visual Studio?