Currently the Antlr4.Runtime.Standard NuGet package only contains a netstandard 2.0 build. If you consume such a package targeting .NET Framework prior to 4.7.2 it adds additional dependencies that causes us some issues. Instead of working around those it would be easier if the C# runtime package included a .NET Framework 4.6.2 target.

<TargetFrameworks>net462;netstandard2.0</TargetFrameworks>

We cannot upgrade to 4.7.2 or newer right now due to outside constraints for some of our projects.