Visual studio cast is redundant when passing arguments using reflection

With this line of code, VS20125 shows "Cast is redundant" for both arguments (but works!!).

Activator.CreateInstance(type, (IOperationContext)null, (Dictionary<string, object>)null);

Whereas if I remove them I get:

Activator.CreateInstance(type, null, null);

It throws "System.MissingMethodException" exception:

Constructor on type 'iBI.Services.Hsd.Operations.Schedule.RefreshUsedOperation' not found.

Is there something wrong with the usage or this is just false alram by visual studio?