How to fix "Could not retrieve project assembly output path" after upgrading from .NET Framwork to .NET

Hi

I've had this error as well. The reason was that the build skipped the project containing the form (or in my case a user control) and that caused the error about not finding the output path.

The solution was to manually correct the solution file (.sln) and make sure that the build settings were the same for all projects. (The Configuration Manager didn't indicate any problem!)

	{922EC095-EC00-4254-832D-7552D59EBF2C}.Debug|x64.ActiveCfg = Debug|x64  
	{922EC095-EC00-4254-832D-7552D59EBF2C}.Debug|x64.Build.0 = Debug|x64  
	{922EC095-EC00-4254-832D-7552D59EBF2C}.Release|x64.ActiveCfg = Release|x64  
	{922EC095-EC00-4254-832D-7552D59EBF2C}.Release|x64.Build.0 = Release|x64

RE: Visual Studio 2026, Winforms application

I had the same problem after changing my 'TargetFrameworks' while attempting to move some projects over to .NET10. I had issues and rolled back to .NET8.0. Afterwards, on a specific project I had the above failure.

The development solution has about 12 projects in it. Only one of them had the above error.

Solution: I closed the solution and opened up just the one offending project file. Then I could load the form correctly and then saved it. I then closed the Project and re-opened the solution once again. I could now load forms from the Project that had previously failed.

Hi @יוסף שלי , Welcome to Microsoft Q&A,

There is a possibility that although it was migrated the path of the link did not change.

1. Go to Manage Workspaces (either via the File/Source Control menu or the Workspace drop-down list in Source Control Explorer)
2. Select Edit for the workspace.
3. You should see a mapping of the source control directory under the "Working Folders" added to the old/wrong project directory.
4. Select it and click Delete.
5. Close VS and delete the suo file.

It's still referencing the wrong directory, reload your project and you should be good to go.

You can also try deleting the suo file directly and reloading it. The suo file may be hidden and you need to show it manually. Best Regards,

Jiale

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