Add Face in Microsoft faces throwing error

Hi All,

I am trying to use add face and detect face activity from Microsoft face for my Project. i have installed the packages related to the Microsoft Face in my project. Not sure why i am getting the below error.

is there any specific package that i need to install to use Azure services?

Any help you can give would be greatly appreciated.

Add Face: Method not found: ‘System.Threading.Tasks.Task1<System.Collections.Generic.IList1<Microsoft.Azure.CognitiveServices.Vision.Face.Models.PersonGroup>> Microsoft.Azure.CognitiveServices.Vision.Face.PersonGroupOperationsExtensions.ListAsync(Microsoft.Azure.CognitiveServices.Vision.Face.IPersonGroupOperations, System.String, System.Nullable`1, System.Threading.CancellationToken)’.