Microsoft is under fire in the .NET community now that it is replacing the free .NET Upgrade Assistant with GitHub Copilot App Modernization. This is an AI-driven migration tool that only works with a paid Copilot subscription.
The new approach is intended to make migrations faster and easier, but developers report that it is difficult to use and that the replacement is less reliable than the original tool.
In a blog post, Microsoft describes how Visual Studio 2026 and recent builds of Visual Studio 2022 can start a modernization process via Copilot Chat. The AI agent analyzes the application, makes suggestions for adjustments, and automatically implements changes.
Microsoft claims that this makes migrations significantly faster, but experiences from the community paint a different picture. In comments below the blog, one user reports that Copilot introduced nuget packages during a migration that do not exist at all.
Another developer calls the new approach less professional and much less predictable than the original Upgrade Assistant, which he says offered a clear and structured process. Examples are also given of teams spending hundreds of hours of extra work repairing a failed partial upgrade.
Functionality now behind paywall
According to DevClass, the criticism is not only focused on the technical shortcomings, but mainly on the fact that a previously free option is now part of a subscription model. Developers are frustrated that functionality they have been using free of charge for years is now disappearing behind a paywall. In addition, the use of the new tool is mandatory linked to Copilot Pro, Pro+, Business, or Enterprise. Without a license, the modernization feature simply does not work.
In its blog responses, Microsoft emphasizes that the old Upgrade Assistant is still available in Visual Studio 2026, although it is disabled by default. Anyone who wants to use it must enable a hidden setting via the Options menu. The way in which the option is hidden, including a prompt encouraging users to try Copilot, is not appreciated by everyone.
Migrating from .NET Framework to modern .NET remains a challenge for many organizations, especially for applications that depend on Windows-specific components such as COM objects, registry access, and custom services. During Ignite 2025, Microsoft introduced Managed Instance for Azure App Service, a service specifically designed to support this type of legacy functionality.
The introduction of Copilot as a replacement for traditional tooling underscores the direction Microsoft wants to take, but reactions from the field show that AI does not automatically lead to better or more reliable development experiences.