08-13 12:15:51.419 E/mono ( 1516): System.NullReferenceException: Object reference not set to an instance of an object.

[john1726]

When I attempt to run, I get this error:

An unhandled exception occured.

08-13 12:15:51.419 E/mono    ( 1516): 
08-13 12:15:51.419 E/mono    ( 1516): Unhandled Exception:
08-13 12:15:51.419 E/mono    ( 1516): System.NullReferenceException: Object reference not set to an instance of an object.
08-13 12:15:51.419 E/mono    ( 1516):   at (wrapper dynamic-method) System.Object:841dfca9-313d-4d04-b6fc-473c386af2df (intptr,intptr,bool,int,int,int,int)
08-13 12:15:51.419 E/mono    ( 1516):   at (wrapper native-to-managed) System.Object:841dfca9-313d-4d04-b6fc-473c386af2df (intptr,intptr,int,int,int,int,int)
In mgmain JNI_OnLoad
08-13 12:15:51.419 E/mono-rt ( 1516): [ERROR] FATAL UNHANDLED EXCEPTION: System.NullReferenceException: Object reference not set to an instance of an object.
08-13 12:15:51.419 E/mono-rt ( 1516):   at (wrapper dynamic-method) System.Object:841dfca9-313d-4d04-b6fc-473c386af2df (intptr,intptr,bool,int,int,int,int)
08-13 12:15:51.419 E/mono-rt ( 1516):   at (wrapper native-to-managed) System.Object:841dfca9-313d-4d04-b6fc-473c386af2df (intptr,intptr,int,int,int,int,int)

Do you have any suggestions? TIA.

UPDATE:

This is the line where it is throwing the exception:

            var auth = new OAuth2Authenticator (
                clientId: App.Instance.OAuthSettings.ClientId, // your OAuth2 client id
                scope: App.Instance.OAuthSettings.Scope, // The scopes for the particular API you're accessing. The format for this will vary by API.
                authorizeUrl: new Uri (App.Instance.OAuthSettings.AuthorizeUrl), // the auth URL for the service
                redirectUrl: new Uri (App.Instance.OAuthSettings.RedirectUrl)); // the redirect URL for the service