Code generation for classes which inherit Interface fails

[LiverpoolOwen]

When generating GraphQL client code for objects which inherit from an interface I am seeing the following errors:

"C:\Users\pierceo\.nuget\packages\tocsoft.graphqlcodegen.msbuild\0.1.0-beta0011\tasks\binaries\net461\Tocsoft.GraphQLCodeGen.Cli.exe" "C:\Users\pierceo\Source\Repos\crisp.server\Crisp.Extranet\CrispQueries\address-lookup.gql" "C:\Users\pierceo\Source\Repos\crisp.server\Crisp.Extranet\CrispQueries\CompaniesHouseSearch.gql" "C:\Users\pierceo\Source\Repos\crisp.server\Crisp.Extranet\CrispQueries\CompanyDetails.gql" "C:\Users\pierceo\Source\Repos\crisp.server\Crisp.Extranet\CrispQueries\CurrentUser.gql" "C:\Users\pierceo\Source\Repos\crisp.server\Crisp.Extranet\CrispQueries\GenericEmail.gql" "C:\Users\pierceo\Source\Repos\crisp.server\Crisp.Extranet\CrispQueries\legalFormTypes.gql" "C:\Users\pierceo\Source\Repos\crisp.server\Crisp.Extranet\CrispQueries\Order.gql" "C:\Users\pierceo\Source\Repos\crisp.server\Crisp.Extranet\CrispQueries\Orders.gql" "C:\Users\pierceo\Source\Repos\crisp.server\Crisp.Extranet\CrispQueries\PersonRegistration.gql" "C:\Users\pierceo\Source\Repos\crisp.server\Crisp.Extranet\CrispQueries\Quote.gql" "C:\Users\pierceo\Source\Repos\crisp.server\Crisp.Extranet\CrispQueries\QuoteApplication.gql" "C:\Users\pierceo\Source\Repos\crisp.server\Crisp.Extranet\CrispQueries\Quotes.gql" "C:\Users\pierceo\Source\Repos\crisp.server\Crisp.Extranet\CrispQueries\RegisteredCompanyList.gql" "C:\Users\pierceo\Source\Repos\crisp.server\Crisp.Extranet\CrispQueries\RespondToCondition.gql" "C:\Users\pierceo\Source\Repos\crisp.server\Crisp.Extranet\CrispQueries\roles.gql" "C:\Users\pierceo\Source\Repos\crisp.server\Crisp.Extranet\CrispQueries\UnitTypeList.gql" "C:\Users\pierceo\Source\Repos\crisp.server\Crisp.Extranet\CrispQueries\warranty-providors.gql" "C:\Users\pierceo\Source\Repos\crisp.server\Crisp.Extranet\Views\QuoteApplication\ClientApp\app\containers\quote-application\QuoteApplication.gql" --msbuild-outputdir "C:\Users\pierceo\AppData\Local\Temp\2a7e759b-72df-4c7a-a572-b1ff31b19019"
C:\Users\pierceo\Source\Repos\crisp.server\Crisp.Extranet\CrispQueries\CompanyDetails.gql(14,13): ERROR GQL0002: The field 'name' in not a valid member of 'Person'
C:\Users\pierceo\Source\Repos\crisp.server\Crisp.Extranet\CrispQueries\CompanyDetails.gql(25,9): ERROR GQL0002: The field 'address' in not a valid member of 'Office'
C:\Users\pierceo\Source\Repos\crisp.server\Crisp.Extranet\CrispQueries\CompanyDetails.gql(34,11): ERROR GQL0002: The field 'address' in not a valid member of 'Office'
C:\Users\pierceo\Source\Repos\crisp.server\Crisp.Extranet\CrispQueries\CompanyDetails.gql(45,11): ERROR GQL0002: The field 'employees' in not a valid member of 'Office'
C:\Users\pierceo\Source\Repos\crisp.server\Crisp.Extranet\CrispQueries\CurrentUser.gql(9,6): ERROR GQL0002: The field 'name' in not a valid member of 'Person'
ERROR GQL0001: System.NullReferenceException: Object reference not set to an instance of an object.
   at Tocsoft.GraphQLCodeGen.ObjectModel.Selections.FieldSelection.Resolve(GraphQLDocument doc, IGraphQLFieldCollection rootType) in C:\projects\graphqlcodegen\Tocsoft.GraphQLCodeGen.Cli\ObjectModel\Selections\FieldSelection.cs:line 52
   at Tocsoft.GraphQLCodeGen.ObjectModel.Selections.SetSelection.Resolve(GraphQLDocument doc, IGraphQLType rootType) in C:\projects\graphqlcodegen\Tocsoft.GraphQLCodeGen.Cli\ObjectModel\Selections\SetSelection.cs:line 64
   at Tocsoft.GraphQLCodeGen.ObjectModel.Selections.FieldSelection.Resolve(GraphQLDocument doc, IGraphQLFieldCollection rootType) in C:\projects\graphqlcodegen\Tocsoft.GraphQLCodeGen.Cli\ObjectModel\Selections\FieldSelection.cs:line 70
   at Tocsoft.GraphQLCodeGen.ObjectModel.Selections.SetSelection.Resolve(GraphQLDocument doc, IGraphQLType rootType) in C:\projects\graphqlcodegen\Tocsoft.GraphQLCodeGen.Cli\ObjectModel\Selections\SetSelection.cs:line 64
   at Tocsoft.GraphQLCodeGen.ObjectModel.Selections.FieldSelection.Resolve(GraphQLDocument doc, IGraphQLFieldCollection rootType) in C:\projects\graphqlcodegen\Tocsoft.GraphQLCodeGen.Cli\ObjectModel\Selections\FieldSelection.cs:line 70
   at Tocsoft.GraphQLCodeGen.ObjectModel.Selections.SetSelection.Resolve(GraphQLDocument doc, IGraphQLType rootType) in C:\projects\graphqlcodegen\Tocsoft.GraphQLCodeGen.Cli\ObjectModel\Selections\SetSelection.cs:line 64
   at Tocsoft.GraphQLCodeGen.ObjectModel.Selections.FieldSelection.Resolve(GraphQLDocument doc, IGraphQLFieldCollection rootType) in C:\projects\graphqlcodegen\Tocsoft.GraphQLCodeGen.Cli\ObjectModel\Selections\FieldSelection.cs:line 70
   at Tocsoft.GraphQLCodeGen.ObjectModel.Selections.SetSelection.Resolve(GraphQLDocument doc, IGraphQLType rootType) in C:\projects\graphqlcodegen\Tocsoft.GraphQLCodeGen.Cli\ObjectModel\Selections\SetSelection.cs:line 64
   at Tocsoft.GraphQLCodeGen.ObjectModel.Selections.FieldSelection.Resolve(GraphQLDocument doc, IGraphQLFieldCollection rootType) in C:\projects\graphqlcodegen\Tocsoft.GraphQLCodeGen.Cli\ObjectModel\Selections\FieldSelection.cs:line 70
   at Tocsoft.GraphQLCodeGen.ObjectModel.Selections.SetSelection.Resolve(GraphQLDocument doc, IGraphQLType rootType) in C:\projects\graphqlcodegen\Tocsoft.GraphQLCodeGen.Cli\ObjectModel\Selections\SetSelection.cs:line 64
   at Tocsoft.GraphQLCodeGen.ObjectModel.Selections.FieldSelection.Resolve(GraphQLDocument doc, IGraphQLFieldCollection rootType) in C:\projects\graphqlcodegen\Tocsoft.GraphQLCodeGen.Cli\ObjectModel\Selections\FieldSelection.cs:line 70
   at Tocsoft.GraphQLCodeGen.ObjectModel.Selections.SetSelection.Resolve(GraphQLDocument doc, IGraphQLType rootType) in C:\projects\graphqlcodegen\Tocsoft.GraphQLCodeGen.Cli\ObjectModel\Selections\SetSelection.cs:line 64
   at Tocsoft.GraphQLCodeGen.ObjectModel.Operation.Resolve(GraphQLDocument doc) in C:\projects\graphqlcodegen\Tocsoft.GraphQLCodeGen.Cli\ObjectModel\Operation.cs:line 45
   at Tocsoft.GraphQLCodeGen.ObjectModel.GraphQLDocument..ctor(GraphQLDocument ast, IEnumerable`1 queryParts) in C:\projects\graphqlcodegen\Tocsoft.GraphQLCodeGen.Cli\ObjectModel\GraphQLDocument.cs:line 76
   at Tocsoft.GraphQLCodeGen.IntrospectedSchemeParser.Parse(IEnumerable`1 parts) in C:\projects\graphqlcodegen\Tocsoft.GraphQLCodeGen.Cli\IntrospectedSchemeParser.cs:line 41
C:\Users\pierceo\Source\Repos\crisp.server\Crisp.Extranet\CrispQueries\PersonRegistration.gql(6,7): ERROR GQL0002: The field 'registrations' in not a valid member of 'Person'
C:\Users\pierceo\AppData\Local\Temp\2a7e759b-72df-4c7a-a572-b1ff31b19019\Crisp.Extranet.GraphQL.AddressLookup.cs
C:\Users\pierceo\AppData\Local\Temp\2a7e759b-72df-4c7a-a572-b1ff31b19019\Crisp.Extranet.GraphQL.GraphQlCompaniesHouseSearch.cs
C:\Users\pierceo\AppData\Local\Temp\2a7e759b-72df-4c7a-a572-b1ff31b19019\Crisp.Extranet.Pages.Email.GraphQlEmailClient.cs
C:\Users\pierceo\AppData\Local\Temp\2a7e759b-72df-4c7a-a572-b1ff31b19019\Crisp.Extranet.GraphQL.LegalFormTypes.cs
C:\Users\pierceo\AppData\Local\Temp\2a7e759b-72df-4c7a-a572-b1ff31b19019\Crisp.Extranet.Pages.Orders.OrdersIndex.cs
C:\Users\pierceo\AppData\Local\Temp\2a7e759b-72df-4c7a-a572-b1ff31b19019\Crisp.Extranet.Pages.Quotes.QuotesIndex.cs
C:\Users\pierceo\AppData\Local\Temp\2a7e759b-72df-4c7a-a572-b1ff31b19019\Crisp.Extranet.GraphQL.GraphQlRegisteredCompanyList.cs
C:\Users\pierceo\AppData\Local\Temp\2a7e759b-72df-4c7a-a572-b1ff31b19019\Crisp.Extranet.Pages.Quotes.GraphQlConditionClient.cs
C:\Users\pierceo\AppData\Local\Temp\2a7e759b-72df-4c7a-a572-b1ff31b19019\Crisp.Extranet.GraphQL.RolesClient.cs
C:\Users\pierceo\AppData\Local\Temp\2a7e759b-72df-4c7a-a572-b1ff31b19019\Crisp.Extranet.GraphQL.UnitTypeList.cs
C:\Users\pierceo\AppData\Local\Temp\2a7e759b-72df-4c7a-a572-b1ff31b19019\Crisp.Extranet.GraphQL.WarrantyProviders.cs
C:\Users\pierceo\AppData\Local\Temp\2a7e759b-72df-4c7a-a572-b1ff31b19019\Crisp.Extranet.Pages.QuoteApplication.GraphQlQuoteApplicationClient.cs