var feedItemService = (FeedItemService)user.GetService(AdWordsService.v201509.FeedItemService);
var feedOperation = new FeedItemOperation{    operand = new FeedItem {                    feedId = 32977028,                    feedItemId = 3161896032,                    attributeValues = new[] {                        new FeedItemAttributeValue                        {                            feedAttributeId = attributeMap[5],                            stringValue = "Oliver custom title"                        }                    }                },    @operator = Operator.SET});
feedItemService.mutate(new [] { feedOperation });Google.Api.Ads.AdWords.Lib.AdWordsApiException was unhandled  HResult=-2146233088  Message=AdWordsApiException: One or more AdWords API errors have occurred. 
API encountered an unexpected internal error.. (Error: InternalApiError.UNEXPECTED_INTERNAL_API_ERROR, FieldPath: , Trigger: )
  Source=Google.Ads.Common  StackTrace:       at Google.Api.Ads.Common.Lib.AdsSoapClient.MakeApiCall(String methodName, Object[] parameters)       at Google.Api.Ads.Common.Lib.AdsSoapClient.Invoke(String methodName, Object[] parameters)       at Google.Api.Ads.AdWords.v201509.FeedItemService.mutate(FeedItemOperation[] operations)       at Etammmore.Adwords.AdwordsFeedItemRepository.UpdateImpl(IReadOnlyCollection`1 feedItems) in C:\Users\*****\Documents\Visual Studio 2015\Projects\AdwordsTest\Etammmore.Adwords\AdwordsFeedItemRepository.cs:line 112       at Etammmore.Adwords.AdwordsFeedContext.SaveChanges() in C:\Users\*****\Documents\Visual Studio 2015\Projects\AdwordsTest\Etammmore.Adwords\AdwordsFeedContext.cs:line 42       at AdwordsTest.Program.Main(String[] args) in C:\Users\*****\Documents\Visual Studio 2015\Projects\AdwordsTest\AdwordsTest\Program.cs:line 36       at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)       at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()       at System.Threading.ThreadHelper.ThreadStart_Context(Object state)       at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)       at System.Threading.ThreadHelper.ThreadStart()  InnerException:        Actor=""       HResult=-2146233087       Lang=""       Message=[InternalApiError.UNEXPECTED_INTERNAL_API_ERROR @ com.google.ads.api.services.common.error.InternalApiError.<init>(InternalApiErro]       Node=""       Role=""       Source=System.Web.Services       StackTrace:            at System.Web.Services.Protocols.SoapHttpClientProtocol.ReadResponse(SoapClientMessage message, WebResponse response, Stream responseStream, Boolean asyncCall)            at System.Web.Services.Protocols.SoapHttpClientProtocol.Invoke(String methodName, Object[] parameters)            at Google.Api.Ads.Common.Lib.AdsSoapClient.MakeApiCall(String methodName, Object[] parameters)       InnerException: 
  AdsClientLibs.DetailedRequestLogs Error: 1 :  -----------------BEGIN API CALL---------------------
  Request  -------
  POST /api/adwords/cm/v201509/FeedItemService  User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; MS Web Services Client Protocol 4.0.30319.42000)  Authorization: ******  VsDebuggerCausalityData: uIDPo18a4dJsoSBJmhEAPWL/MxEAAAAAafK16VD9wki4Ct3q9tVkZ9VripGUGZFEr9ZY4WHII5kACQAA  Content-Type: text/xml; charset=utf-8  SOAPAction: ""  Host: adwords.google.com  Content-Length: 1598  Accept-Encoding: gzip  TimeStamp: Wed, 27 Jan 2016 11:55:35 GMT
  <soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">    <soap:Header>      <RequestHeader xmlns="https://adwords.google.com/api/adwords/cm/v201509">        <developerToken xmlns="https://adwords.google.com/api/adwords/cm/v201509">******</developerToken>        <clientCustomerId xmlns="https://adwords.google.com/api/adwords/cm/v201509">****-***-***</clientCustomerId>        <userAgent xmlns="https://adwords.google.com/api/adwords/cm/v201509">******* (AwApi-DotNet/18.21.0, Common-Dotnet/3.11.0, .NET CLR/4.0.30319.42000, gzip)</userAgent>      </RequestHeader>    </soap:Header>    <soap:Body>      <mutate xmlns="https://adwords.google.com/api/adwords/cm/v201509">        <operations>          <operator>SET</operator>          <operand>            <feedId>32977028</feedId>            <feedItemId>3162131847</feedItemId>            <attributeValues>              <feedAttributeId>1</feedAttributeId>              <stringValue>Room-103451</stringValue>            </attributeValues>            <attributeValues>              <feedAttributeId>2</feedAttributeId>              <stringValue>123123 VSAdasd</stringValue>            </attributeValues>            <attributeValues>              <feedAttributeId>3</feedAttributeId>              <stringValues>http://*******.dk/Værelser/103451/123123-vsadasd</stringValues>            </attributeValues>            <attributeValues>              <feedAttributeId>4</feedAttributeId>              <stringValue>http://*******.dk//ProfilePictures/143608_Wide_290x195.jpg</stringValue>            </attributeValues>            <attributeValues>              <feedAttributeId>5</feedAttributeId>              <stringValue>2000.0000 DKK</stringValue>            </attributeValues>          </operand>        </operations>      </mutate>    </soap:Body>  </soap:Envelope>
  Response  --------
  Content-Encoding:  X-Content-Type-Options: nosniff  X-Frame-Options: SAMEORIGIN  X-XSS-Protection: 1; mode=block  Content-Length: 535  Cache-Control: private, max-age=0  Content-Type: text/xml; charset=UTF-8  Date: Wed, 27 Jan 2016 10:55:34 GMT  Expires: Wed, 27 Jan 2016 10:55:34 GMT  Server: GSE  TimeStamp: Wed, 27 Jan 2016 11:55:35 GMT
  <soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">    <soap:Header>      <ResponseHeader xmlns="https://adwords.google.com/api/adwords/cm/v201509">        <requestId>00052a4ea4327c490a816146fd07a804</requestId>        <serviceName>FeedItemService</serviceName>        <methodName>mutate</methodName>        <operations>1</operations>        <responseTime>111</responseTime>      </ResponseHeader>    </soap:Header>    <soap:Body>      <soap:Fault>        <faultcode>soap:Server</faultcode>        <faultstring>[InternalApiError.UNEXPECTED_INTERNAL_API_ERROR @ com.google.ads.api.services.common.error.InternalApiError.<init>(InternalApiErro]</faultstring>        <detail>          <ApiExceptionFault xmlns="https://adwords.google.com/api/adwords/cm/v201509">            <message>[InternalApiError.UNEXPECTED_INTERNAL_API_ERROR @ com.google.ads.api.services.common.error.InternalApiError.<init>(InternalApiErro]</message>            <ApplicationException.Type>ApiException</ApplicationException.Type>            <errors xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:type="InternalApiError">              <fieldPath></fieldPath>              <trigger></trigger>              <errorString>InternalApiError.UNEXPECTED_INTERNAL_API_ERROR</errorString>              <ApiError.Type>InternalApiError</ApiError.Type>              <reason>UNEXPECTED_INTERNAL_API_ERROR</reason>            </errors>          </ApiExceptionFault>        </detail>      </soap:Fault>    </soap:Body>  </soap:Envelope>