Could not load file or assembly 'System.Runtime, Version=4.2.0.0' or one of its dependencies

[babula38]

blow are some details which might help you.

• Visual studio version:- vs2019 community latest preview.
• Expression tree version:- took latest from the github release
• .Net Framework used:- .net core 3.1 with xunit project.

below is the expression.

.Lambda #Lambda1<System.Func`3[MyExpression.lib.test.MyClass,MyExpression.lib.test.MyClass1,MyExpression.lib.test.MyClass]>(
    MyExpression.lib.test.MyClass $myClass,
    MyExpression.lib.test.MyClass1 $myclass1) {
    .Block() {
        .Block() {
            $myClass.MyProperty = $myclass1.MyProperty;
            $myClass.MyProperty = $myclass1.MyProperty
        };
        $myClass
    }
}

Do let me know if you some other information also.

[zspitz]

I'm not sure why this happens; but other people have reported it as well. (#103).

I haven't been able to duplicate this.

You can workaround this by installing the visualizer to the Visual Studio install path, instead of the subfolder under Documents, as described here.

[babula38]

I have placed the dll inside Visual studio install path, i am getting the below error now.

Unable to perform function evaluation on the process being debugged.

Additional information:- 
Evaluation timed out

at Microsoft.VisualStudio.DebuggerVisualizers.Impl.VisualizerObjectProvider.Create(IVisualizerObjectProviderInternal visualizerObjectProviderInternal)
at ClrCustomVisualizerVSHost.ClrCustomVisualizerVSHostHelper.DisplayValue(IntPtr hWnd, SuccessEvaluationResultProxy evaluationResult, Int32 selectedIndex, DkmApiVersion protocolVersion)

But one thing i noticed, once i called the .Compile() on the expression it started working. Is this expected?

[zspitz]

Once you called .Compile() on the expression, you can open the visualizer on the original expression, not on the result of the compilation? That's rather strange.

Could you add a reference to https://www.nuget.org/packages/ExpressionTreeToString/ and call the ToString extension method on your expression?

// using ExpressionTreeToString;
Expression expr = ...
var tostring = expr.ToString("Object notation");

[zspitz]

A possibly relevant link: dotnet/standard#481 (comment)

[zspitz]

I've isolated this to the use of Costura on the debugger side; using Costura on the debuggee side doesn't cause a problem.

Also, the problem is only with .NET Core projects.

[zspitz]

@babula38 Could you try the latest release? And install to the VS install path.

[babula38]

@zspitz thanks, it is working now, if I install it in visual studio installer directory.