An error "The framework 'Microsoft.NETCore.App', version '6.0.0-preview.3.21168.7' was not found" pops up after installed .net 6.0 Preview 3 latest build from master branch

[Amy-Li03]

Repro steps:

1. Install SDK 6.0 preview 3 from master branch of https://github.com/dotnet/installer
2. Create a WinForms net core project targeting .NET 6.0.

Actual Result;
An error dialog pops up when loading the form designer.

Expected Result:
The form designer should be load successfully.

[dotnet-issue-labeler]

I couldn't figure out the best area label to add to this issue. If you have write-permissions please help me learn by adding exactly one area label.

[ryalanms]

/cc @dotnet/wpf-developers @RussKie @marcpopMSFT

This impacts all WPF and WinForms applications.

[dotnet-issue-labeler]

I couldn't figure out the best area label to add to this issue. If you have write-permissions please help me learn by adding exactly one area label.

[marcpopMSFT]

dotnet/sdk#16425

[jiangzeng01]

@marcpopMSFT Do you have any idea about when this issue will get fixed? I tried latest 6.0.100-preview.3.21173.8, still same issue, it fails all WinForms/WPF apps now.

[RussKie]

@jiangzeng01 it is probably worth asking this question on the SDK thread.

[L00pZBreak3r]

The issue is still unfixed.

[jiangzeng01]

Same issue here dotnet/sdk#16512 for AppCompat.
115 real world apps failed due to this issue in AppCompat lab

[Amy-Li03]

Installed the latest build: .NET SDK 6.0.100-preview.4.21178.4 from master branch of https://github.com/dotnet/installer, this issue has been fixed, we can open the winforms core designer successfully.