There is no option to build solution and open properties of project after retarget to net standard 2.0

Repro

• I created new solution with project targeted net 4.6.1 and its test project.
• Project was copied from solution created in VS 2017
• I have changed <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion> to <TargetFramework>netstandard2.0</TargetFramework> for both unit test and library project (<OutputType>Library</OutputType>).

Now I cannot build solution. When I open project properties window I see error:

An error occurred trying to load the project properties window.  Close the window and try again. Member not found. (Exception from HRESULT: 0x80020003 (DISP_E_MEMBERNOTFOUND))

Answer

I had to replace:

<Project ToolsVersion="15.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">

to:

<Project Sdk="Microsoft.NET.Sdk">

In my csproj file

Source: https://arminreiter.com/2017/05/port-net-framework-net-standard/