Network Performance Test - Could not load type 'Microsoft.VisualStudio.WebTesting.SharepointInformation'

TL; DR:

• Check the set prerequisites in the last part Create a network performance and load project
• In my case, replacing the original file C: \ Windows \ assembly \ GAC_MSIL \ Microsoft.VisualStudio.QualityTools.WebTestFramework \ 10.0.0.0__b03f5f7f11d50a3a \ Microsoft.VisualStudio.QualityTools.WebTestFramework.dll with C: \ Microsoft Visual Studio (x86) \ \ 2017 \ Enterprise \ Common7 \ IDE \ ReferenceAssemblies \ v4.0 \ Microsoft.VisualStudio.QualityTools.WebTestFramework.dll solved the problem.

I tackled the same problem. Every time I created a Web Performance and Load Test Project in Visual Studio 2017 Enterprise (with an arbitrary version of the .NET Framework), I got the same error when I tried to open the * .webtest file. The VS UI seemed incomplete and the toolbar sometimes shows null exceptions.

At first I thought I had an incomplete installation, according to Create Web Performance and Upload Test Project . I even tried to completely uninstall and reinstall said packages. Unfortunately it didn't help. I also experimented with adding and removing reference to Microsoft.VisualStudio.QualityTools.WebTestFramework as there are multiple options in my reference browser but no luck.

There is little information about the WebTesting.SharepointInformation namespace. After a while, I discovered the existence of Microsoft.VisualStudio.QualityTools.WebTest.SharePoint.dll and after a closer look, I noticed that it refers to the QualityTools.WebTestFramework assembly in C: \ Windows \ assembly \ ... which has the same assembly version and public key token, but smaller than the one contained in the VS 2017 installation. I replaced it with VS2017 one and voila, * .webtest can be opened successfully.