The It.IsAny<T>()
call is a method so needs parentheses after it:
UIServicemock.Setup(u => u.ShowDialog(It.IsAny<string>(), It.IsAny<string>(),
It.IsAny<Dictionary<string,object>>(),
It.IsAny<Action<Dictionary<string, object>>>(),
It.IsAny<Dictionary<string,object>>()));