nameof with generic types

This is expected. According to the documentation, your expression is disallowed, because it refers to an unbound generic type:

Because the argument needs to be an expression syntactically, there are many things disallowed that are not useful to list. The following are worth mentioning that produce errors: predefined types (for example, int or void), nullable types (Point?), array types (Customer[,]), pointer types (Buffer*), qualified alias (A::B), and unbound generic types (Dictionary<,>), preprocessing symbols (DEBUG), and labels (loop:).

You can work around this limitation by supplying a generic parameter:

nameof(IGenericInterface<object>.Method)

Note: I think Microsoft should tweak nameof feature to allow references to methods of unbound generic types.