VisualStudio UWP/XAML Designer not showing UserControl | The element "foo" could not be displayed due to missing assemblies

I have two Projects in my project folder:

• HtSuite.UWP | Library
• HtSuite.UWP.Leitstand | Applicaton

In the Library is an UserControl NamePasswordControl, which I can edit without any problems in the XAML | Designer.

When I place the NamePasswordControl on my LoginView.xaml (which is also in the Library), I got the following error:

the element "passwordView" could not be displayed due to missing assemblies. After building the application, you may be able to view this control

When I run the Application, everything is working as expected.

The following steps I tried so far (without success):

• clean solution
• rebuild project
• deleted cache
• dotnet clean
• dotnet restore
• restarted windows
• updated VisualStudio (v16.6.0) and tried v16.7.0 preview 1

Anyone know how I can get the preview fixed?

minimal test project with same behavior:

https://files.dominic-jonas.de/stackoverflow/ClassLibrary2.zip

A class library in which there is a UserControl and a page on which should be displayed. However, the error is also displayed there and a preview is not possible

Log

• 28.05.2020 Nico Zhu - MSFT could successfully load the preview of the TestProject (visual studio 2017 v15.9.17). I could not display the preview with vs2017.

• https://docs.microsoft.com/en-us/answers/questions/33146/preview-of-usercontrols-not-working-in-a-class-lib.html
• https://developercommunity.visualstudio.com/content/problem/1052332/uwpxaml-designer-not-showing-usercontrol-the-eleme.html