Roslyn Analyzer Test Project Upgrade Fix: Replacing Obsolete MSTest Packages in .NET 10

Published 28/06/2026

Description

In this video, I show how to fix a frustrating Roslyn analyzer test project upgrade issue in C# after updating NuGet packages and moving a test project from .NET 9 to .NET 10. Contents: 0:00 - Introduction 0:10 - Description 0:44 - The Problem 1:44 - The Fix 2:42 - Obsolete Wizard 3:07 - Online Doc 3:44 - Conclusion Microsoft deprecated several Roslyn testing packages ending in .MSTest, but the documentation is still limited and even the Visual Studio 20262026 analyzer/code fix project wizard can still generate outdated references. That means you can upgrade your solution, follow the normal process, and still end up with obsolete test package references in your project. I walk through: How the issue appears after a standard NuGet package upgrade Why packages ending in .MSTest are now obsolete The quick fix: removing .MSTest from the affected package references How to refresh NuGet and install the correct replacement packages Why the project still builds without changing your analyzer test code Where Microsoft’s GitHub documentation mentions the change Why the current wizard output is still misleading If you are maintaining a Roslyn analyzer, code fix, or source generator test project, this will save you time and help you avoid getting stuck on package deprecations with almost no clear guidance. Don’t forget to like, subscribe, and leave a comment if you want more videos about .net. #dotnet #csharp #roslyn GitHub : https://l.samayas.eu/9bJC5ArAVC Follow me on X: https://l.samayas.eu/jo3eaYEf3E?P=YT&V=135 Buy me a Coffee : https://l.samayas.eu/jX6xL7EWhd?P=YT&V=135 Studio Equipment Camera Sony Alpha ZV-E10 II: https://l.samayas.eu/k7y95TREl0?P=YT&V=135 Secondary Camera Obsbot Tail Air: https://l.samayas.eu/iFQu9WfmCw?P=YT&V=135 Elgato Prompter: https://l.samayas.eu/fHVrqqXtSc?P=YT&V=135 Microphone Rode Wireless GO II: https://l.samayas.eu/afBINjiBXN?P=YT&V=135