error after visual studio update

Hello Mahmoud,

This error usually occurs when the designer cannot complete its design-time build. Since it started immediately after updating to Visual Studio 2022 version 17.14.0, first update Visual Studio to the latest available 17.14 servicing release, because later updates include stability and bug fixes.

Then try the following steps:

1. Close the designer window.
2. Select Build > Clean Solution.
3. Select Build > Rebuild Solution.
4. Confirm that the solution builds without compilation errors.

Microsoft recommends cleaning and rebuilding first because compilation errors, invalid dependencies, or temporary design-time files can prevent the Windows Forms Designer from loading.

If the issue persists:

1. Close Visual Studio.
2. Delete the following folders from the solution directory:

.vs
bin
obj

1. Reopen Visual Studio.
2. Restore the NuGet packages and rebuild the solution.
3. Try opening the form in the designer again.

Also check the following:

• Verify that the form class inherits from System.Windows.Forms.Form.
• Make sure the form and its base class are not abstract.
• Check whether the form constructor or static initialization code accesses a database, configuration file, environment variable, network resource, or service unavailable at design time.
• Temporarily disable or remove recently updated third-party controls and extensions.
• Test whether the problem also occurs in a newly created Windows Forms project targeting the same framework.

The designer error page may contain a yellow expandable section with the exact class, file, line, exception, and call stack that prevented the designer from loading. Please expand it and share the complete error message, along with:

• The full Visual Studio version from Help > About Microsoft Visual Studio
• The project type: Windows Forms, WPF, or another designer
• The target framework
• Whether the issue affects all forms or only one form
• Whether a new project has the same problem

This information will help determine whether the issue is related to the Visual Studio update, the project configuration, a dependency, or code executed at design time.

If this answer resolves the issue, please mark it as Accepted Answer so it can help other users with the same problem.