Indeed, dragging a nullable up from a port does freeze the browser (because of an unhandles exception on the browser thread). I have hotfixed this and can send you the temp fix to your registered email if you like (just let me know).
In regards to the AOTClasses generator, can you please post the error for me? Can you please confirm that the generated AOTClasses.cs file does include a line like this: System.Nullable<UnityEngine.Vector3> System_Nullable_UnityEngine_Vector3; ?
Gavalakis
