System.InvalidCastException when running NSwag via MSBuild

When I execute NSwag ("runtime": "NetCore31") via NSwag.MSBuild v13.7.0 on the following file, I get a System.InvalidCastException:

2>Executing file 'nswag.json' with variables 'Configuration=Debug'...
2>System.InvalidCastException: Unable to cast object of type 'NSwag.OpenApiResponse' to type 'NJsonSchema.JsonSchema'.
2>   at NJsonSchema.References.JsonReferenceBase`1.NJsonSchema.References.IJsonReferenceBase.set_Reference(IJsonReference value)
2>   at NJsonSchema.JsonSchemaReferenceUtilities.JsonReferenceUpdater.VisitJsonReferenceAsync(IJsonReference reference, String path, String typeNameHint)
2>   at NJsonSchema.Visitors.AsyncJsonReferenceVisitorBase.VisitAsync(Object obj, String path, String typeNameHint, ISet`1 checkedObjects, Action`1 replacer)
2>   at NJsonSchema.Visitors.AsyncJsonReferenceVisitorBase.VisitAsync(Object obj, String path, String typeNameHint, ISet`1 checkedObjects, Action`1 replacer)
2>   at NJsonSchema.Visitors.AsyncJsonReferenceVisitorBase.VisitAsync(Object obj, String path, String typeNameHint, ISet`1 checkedObjects, Action`1 replacer)
2>   at NJsonSchema.Visitors.AsyncJsonReferenceVisitorBase.VisitAsync(Object obj, String path, String typeNameHint, ISet`1 checkedObjects, Action`1 replacer)
2>   at NJsonSchema.Visitors.AsyncJsonReferenceVisitorBase.VisitAsync(Object obj, String path, String typeNameHint, ISet`1 checkedObjects, Action`1 replacer)
2>   at NJsonSchema.Visitors.AsyncJsonReferenceVisitorBase.VisitAsync(Object obj, String path, String typeNameHint, ISet`1 checkedObjects, Action`1 replacer)
2>   at NJsonSchema.Visitors.AsyncJsonReferenceVisitorBase.VisitAsync(Object obj, String path, String typeNameHint, ISet`1 checkedObjects, Action`1 replacer)
2>   at NJsonSchema.Visitors.AsyncJsonReferenceVisitorBase.VisitAsync(Object obj, String path, String typeNameHint, ISet`1 checkedObjects, Action`1 replacer)
2>   at NJsonSchema.Visitors.AsyncJsonReferenceVisitorBase.VisitAsync(Object obj, String path, String typeNameHint, ISet`1 checkedObjects, Action`1 replacer)
2>   at NJsonSchema.Visitors.AsyncJsonReferenceVisitorBase.VisitAsync(Object obj, String path, String typeNameHint, ISet`1 checkedObjects, Action`1 replacer)
2>   at NJsonSchema.Visitors.AsyncJsonReferenceVisitorBase.VisitAsync(Object obj)
2>   at NJsonSchema.JsonSchemaReferenceUtilities.JsonReferenceUpdater.VisitAsync(Object obj)
2>   at NJsonSchema.JsonSchemaReferenceUtilities.UpdateSchemaReferencesAsync(Object rootObject, JsonReferenceResolver referenceResolver, IContractResolver contractResolver)
2>   at NJsonSchema.Infrastructure.JsonSchemaSerialization.FromJsonAsync[T](String json, SchemaType schemaType, String documentPath, Func`2 referenceResolverFactory, IContractResolver contractResolver)
2>   at NSwag.OpenApiDocument.FromJsonAsync(String data, String documentPath, SchemaType expectedSchemaType, Func`2 referenceResolverFactory) in C:\projects\nswag\src\NSwag.Core\OpenApiDocument.cs:line 190
2>   at NSwag.OpenApiDocument.FromFileAsync(String filePath) in C:\projects\nswag\src\NSwag.Core\OpenApiDocument.cs:line 211
2>   at NSwag.Commands.OutputCommandBase.ReadSwaggerDocumentAsync(String input) in C:\projects\nswag\src\NSwag.Commands\Commands\OutputCommandBase.cs:line 53
2>   at NSwag.Commands.Generation.FromDocumentCommand.RunAsync() in C:\projects\nswag\src\NSwag.Commands\Commands\Generation\FromDocumentCommand.cs:line 62
2>   at NSwag.Commands.Generation.FromDocumentCommand.RunAsync(CommandLineProcessor processor, IConsoleHost host) in C:\projects\nswag\src\NSwag.Commands\Commands\Generation\FromDocumentCommand.cs:line 53
2>   at NSwag.Commands.NSwagDocumentBase.GenerateSwaggerDocumentAsync() in C:\projects\nswag\src\NSwag.Commands\NSwagDocumentBase.cs:line 280
2>   at NSwag.Commands.NSwagDocument.ExecuteAsync() in C:\projects\nswag\src\NSwag.Commands\NSwagDocument.cs:line 81
2>   at NSwag.Commands.Document.ExecuteDocumentCommand.ExecuteDocumentAsync(IConsoleHost host, String filePath) in C:\projects\nswag\src\NSwag.Commands\Commands\Document\ExecuteDocumentCommand.cs:line 86
2>   at NSwag.Commands.Document.ExecuteDocumentCommand.RunAsync(CommandLineProcessor processor, IConsoleHost host) in C:\projects\nswag\src\NSwag.Commands\Commands\Document\ExecuteDocumentCommand.cs:line 32
2>   at NConsole.CommandLineProcessor.ProcessSingleAsync(String[] args, Object input)
2>   at NConsole.CommandLineProcessor.ProcessAsync(String[] args, Object input)
2>   at NConsole.CommandLineProcessor.Process(String[] args, Object input)
2>   at NSwag.Commands.NSwagCommandProcessor.Process(String[] args) in C:\projects\nswag\src\NSwag.Commands\NSwagCommandProcessor.cs:line 56
2>C:\Users\steven.volckaert\Repos\kdc\document-signing-service\src\Connective.ESignatures.Clients\Connective.ESignatures.Clients.csproj(40,5): error MSB3073: The command "dotnet "C:\Users\steven.volckaert\.nuget\packages\nswag.msbuild\13.7.0\buildCrossTargeting\../tools/NetCore31/dotnet-nswag.dll" run nswag.json /variables:Configuration=Debug" exited with code -1.
2>Done building project "Connective.ESignatures.Clients.csproj" -- FAILED.

Any ideas what could be wrong?

The OpenAPI spec can be found in this gist: Connective.ESignatures.OpenApiSpec.v4.yaml

Many thanks for your help!

nswag.json

{
  "runtime": "NetCore31",
  "defaultVariables": null,
  "documentGenerator": {
    "fromDocument": {
      "url": "Connective.ESignatures.OpenApiSpec.v4.yaml",
      "output": null
    }
  },
  "codeGenerators": {
    "openApiToCSharpClient": {
      "clientBaseClass": "Kdc.HttpClientBase",
      "configurationClass": "Kdc.HttpServiceSettings",
      "generateClientClasses": true,
      "generateClientInterfaces": false,
      "clientBaseInterface": null,
      "injectHttpClient": true,
      "disposeHttpClient": false,
      "protectedMethods": [],
      "generateExceptionClasses": true,
      "exceptionClass": "HttpServiceException",
      "wrapDtoExceptions": true,
      "useHttpClientCreationMethod": false,
      "httpClientType": "System.Net.Http.HttpClient",
      "useHttpRequestMessageCreationMethod": true,
      "useBaseUrl": true,
      "generateBaseUrlProperty": false,
      "generateSyncMethods": false,
      "exposeJsonSerializerSettings": false,
      "clientClassAccessModifier": "public",
      "typeAccessModifier": "public",
      "generateContractsOutput": false,
      "contractsNamespace": null,
      "contractsOutputFilePath": null,
      "parameterDateTimeFormat": "s",
      "parameterDateFormat": "yyyy-MM-dd",
      "generateUpdateJsonSerializerSettingsMethod": true,
      "useRequestAndResponseSerializationSettings": false,
      "serializeTypeInformation": false,
      "queryNullValue": "",
      "className": "{controller}Client",
      "operationGenerationMode": "MultipleClientsFromOperationId",
      "additionalNamespaceUsages": [],
      "additionalContractNamespaceUsages": [],
      "generateOptionalParameters": false,
      "generateJsonMethods": false,
      "enforceFlagEnums": false,
      "parameterArrayType": "System.Collections.Generic.IEnumerable",
      "parameterDictionaryType": "System.Collections.Generic.IDictionary",
      "responseArrayType": "System.Collections.Generic.ICollection",
      "responseDictionaryType": "System.Collections.Generic.IDictionary",
      "wrapResponses": false,
      "wrapResponseMethods": [],
      "generateResponseClasses": true,
      "responseClass": "HttpServiceResponse",
      "namespace": "Connective.ESignatures",
      "requiredPropertiesMustBeDefined": true,
      "dateType": "System.DateTime",
      "jsonConverters": null,
      "anyType": "object",
      "dateTimeType": "System.DateTime",
      "timeType": "System.TimeSpan",
      "timeSpanType": "System.TimeSpan",
      "arrayType": "System.Collections.Generic.ICollection",
      "arrayInstanceType": "System.Collections.ObjectModel.Collection",
      "dictionaryType": "System.Collections.Generic.IDictionary",
      "dictionaryInstanceType": "System.Collections.Generic.Dictionary",
      "arrayBaseType": "System.Collections.ObjectModel.Collection",
      "dictionaryBaseType": "System.Collections.Generic.Dictionary",
      "classStyle": "Poco",
      "generateDefaultValues": true,
      "generateDataAnnotations": true,
      "excludedTypeNames": [],
      "excludedParameterNames": [],
      "handleReferences": false,
      "generateImmutableArrayProperties": false,
      "generateImmutableDictionaryProperties": false,
      "jsonSerializerSettingsTransformationMethod": null,
      "inlineNamedArrays": false,
      "inlineNamedDictionaries": false,
      "inlineNamedTuples": true,
      "inlineNamedAny": false,
      "generateDtoTypes": true,
      "generateOptionalPropertiesAsNullable": false,
      "generateNullableReferenceTypes": false,
      "templateDirectory": null,
      "typeNameGeneratorType": null,
      "propertyNameGeneratorType": null,
      "enumNameGeneratorType": null,
      "serviceHost": null,
      "serviceSchemes": null,
      "output": "Connective.ESignatures.Clients.cs",
      "newLineBehavior": "Auto"
    }
  }
}

[RicoSuter]

It seems that the schema references a response which is not a schema and then you get the cast exception… spec seems to be wrong.

[stevenvolckaert]

Thanks for the feedback @RicoSuter!