I am getting an error in Xamarin re: "dynamic registrar". How do I fix this?

If you are using Mono 5.10.x or higher there is a know issue with Xamarin iOS (or Xamarin Forms iOS) where the dynamic linker is removed at runtime. The native libraries will fail to load without the dynamic linker. A work around is to add --optimize=-remove-dynamic-registrar flag to MTouchExtraArgs in the .csproj file . Adding this flag will prevent Mono from removing the dynamic linker. Please see the Mono Dynamic Registrar Flag section of the Starting a New Project page for an example.

This error will appear in your logs similarly to this:

[IceLink] ERROR [FM] 2018/05/09-17:15:45 Error initializing local media.
ObjCRuntime.RuntimeException: Can't register the class FM.IceLink.Opus.Encoder when the dynamic registrar has been linked away.