What is causing visual studio errors looking for defaultbinder.cs?

Question

Just reinstalled visual studio 2019 as I was getting this error: https://github.com/dotnet/roslyn/issues/18814

I have never seen it before. After reinstalling, I no longer see it but I get something else. "Source not found" looking for defaultbinder.cs when running my WPF application from the debugger. Running it outside of the debugger works fine.

I know I have seen this before but I couldn't find any info on the web. -

$exception {"Object reference not set to an instance of an object."} System.NullReferenceException

at System.DefaultBinder.BindToMethod(BindingFlags bindingAttr, MethodBase[] match, Object[]& args, ParameterModifier[] modifiers, CultureInfo cultureInfo, String[] names, Object& state) in f:\dd\ndp\clr\src\BCL\system\defaultbinder.cs:line 66 at MS.Internal.Xaml.Runtime.DynamicMethodRuntime.CreateInstanceWithCtor(Type type, Object[] args) at MS.Internal.Xaml.Runtime.ClrObjectRuntime.CreateInstance(XamlType xamlType, Object[] args)

Answer 1

As Kyle mentioned, just my code should be enabled. This allowed me to start the application. Hope this helps someone else or if no one else, me when I come looking for it a year from now.