I have created a new windows forms project in .NET 5.0. Designer worked but as soon as I add reference to my ASP.NET Core Web API project and try to load Form designer I get message "Timed out while connecting to named pipe". I can run project and it works fine but I can't load Form.
I was able to figure out the problem. Personally, my form had some dependencies that were causing the form not to load. In the Solution Explorer, check to see if you have any 'caution' icons, or try to remove any dependencies.
Follow below steps:
Open your visual studio ----> open your project ------> go to your solution explorer and double click on your project ---> change Target framework To (net472)----->
Again go to your solution explorer and click right on your project and click on properties and change the target framework to 4.7.2
That will successfully and work with me and will work with you
I had the same issue, Open the project file and search for
<ItemGroup>
<FrameworkReference Include="Microsoft.AspNetCore.App" />
</ItemGroup>
Remove this section and the WinForm designer opens with no issues. At least that was my issue.