Collection was modified; enumeration operation may not execute. HELP. What is wrong

[monguso13]

Feedback Type:
Frown (Error)

Timestamp:
2018-11-30T16:40:58.0163865Z

Local Time:
2018-11-30T11:40:58.0163865-05:00

Session ID:
db5721fb-d49d-44d4-ab4e-d43510c644bd

Release:
November 2018

Product Version:
2.64.5285.741 (18.11) (x64)

Stack Trace:
Microsoft.Mashup.Evaluator.Interface.ErrorException: Collection was modified; enumeration operation may not execute. ---> Microsoft.Mashup.Evaluator.Interface.ErrorException: Collection was modified; enumeration operation may not execute. ---> Microsoft.Mashup.Evaluator.Interface.ErrorException: Collection was modified; enumeration operation may not execute. ---> System.InvalidOperationException: Collection was modified; enumeration operation may not execute. ---> System.InvalidOperationException: Collection was modified; enumeration operation may not execute.
at System.ThrowHelper.ThrowInvalidOperationException(ExceptionResource resource)
at System.Collections.Generic.Dictionary`2.Enumerator.MoveNext()
at Microsoft.Mashup.EngineHost.Services.OAuth.OAuthPooledCredentialHandler.Refresh(IResource resource, CredentialDataCollection previousCollection, CredentialDataCollection storageCollection, String referenceId, Boolean forceRefresh)
at Microsoft.Mashup.EngineHost.Services.PooledCredentialService.Refresh(Credential previousCredential, String referenceId, Boolean forceRefresh)
at Microsoft.Mashup.Host.Document.Evaluation.MutexPooledCredentialService.Refresh(Credential previousCredential, String referenceId, Boolean forceRefresh)
at Microsoft.Mashup.EngineHost.CredentialManager.RefreshCredential(Resource resource, Boolean forceRefresh)
at Microsoft.Mashup.EngineHost.Services.CredentialService.RefreshCredential(IResource resource, Boolean forceRefresh)
at Microsoft.Mashup.EngineHost.Services.RemoteCredentialServiceFactory.Stub.<>c__DisplayClass5.<OnRefreshCredentialRequest>b__4()
at Microsoft.Mashup.Evaluator.EvaluationHost.ReportExceptions(String entryName, IEngineHost engineHost, IMessageChannel channel, Action action)
--- End of inner exception stack trace ---
at Microsoft.Mashup.Evaluator.EvaluationHost.<>c__DisplayClass7.<TryReportException>b__6()
at Microsoft.Mashup.Common.SafeExceptions.IgnoreSafeExceptions(IEngineHost host, IHostTrace trace, Action action)
at Microsoft.Mashup.Evaluator.EvaluationHost.TryReportException(IHostTrace trace, IEngineHost engineHost, IMessageChannel channel, Exception exception)
at Microsoft.Mashup.Evaluator.EvaluationHost.ReportExceptions(String entryName, IEngineHost engineHost, IMessageChannel channel, Action action)
at Microsoft.Mashup.Evaluator.MessageHandlers.TryDispatch(IMessageChannel channel, Message message)
at Microsoft.Mashup.Evaluator.ChannelMessenger.ChannelMessageHandlers.TryDispatch(IMessageChannel channel, Message message)
at Microsoft.Mashup.Evaluator.MessageHandlers.Dispatch(IMessageChannel channel, Message message)
at Microsoft.Mashup.Evaluator.ChannelMessenger.OnMessageWithUnknownChannel(IMessageChannel baseChannel, MessageWithUnknownChannel messageWithUnknownChannel)
at Microsoft.Mashup.Evaluator.MessageHandlers.TryDispatch(IMessageChannel channel, Message message)
at Microsoft.Mashup.Evaluator.ChannelMessenger.ChannelMessageHandlers.TryDispatch(IMessageChannel channel, Message message)
at Microsoft.Mashup.Evaluator.MessageHandlers.Dispatch(IMessageChannel channel, Message message)
at Microsoft.Mashup.Evaluator.Interface.IMessageChannelExtensions.WaitFor[T](IMessageChannel channel)
at Microsoft.Mashup.Evaluator.RemotePreviewValueSource.PreviewValueSource.WaitFor(Func`1 condition, Boolean disposing)
at Microsoft.Mashup.Evaluator.RemotePreviewValueSource.PreviewValueSource.get_SmallValue()
at Microsoft.Mashup.Evaluator.Interface.TracingPreviewValueSource.get_SmallValue()
at Microsoft.Mashup.Host.Document.Analysis.PackageDocumentAnalysisInfo.PackagePartitionAnalysisInfo.SetPreviewValue(EvaluationResult2`1 result, Func`1 getStaleSince, Func`1 getSampled)
at Microsoft.Mashup.Host.Document.Analysis.CachingDocumentAnalysisInfo.CachingPartitionAnalysisInfo.SetPreviewValue(EvaluationResult2`1 result, Func`1 getStaleSince, Func`1 getSampled)
at Microsoft.Mashup.DocumentHost.DocumentAnalyzer.Analyze(IPartitionAnalysisInfo partitionInfo, AccessRecorder recorder, EvaluationResult2`1 result, Action`1 callback)
at Microsoft.Mashup.DocumentHost.DocumentAnalyzer.<>c__DisplayClass10.<BeginAnalyzeDocumentPartition>b__d(EvaluationResult2`1 result)
at Microsoft.Mashup.Evaluator.Interface.EvaluationResultExtensions.InvokeThenOnDispose(Action`1 callback, EvaluationResult2`1 result, Action action)
at Microsoft.Mashup.Evaluator.Interface.EvaluationResultExtensions.InvokeThenOnDispose[T](Action`1 callback, EvaluationResult2`1 result, Action action)
at Microsoft.Mashup.Evaluator.LimitedDocumentEvaluatorFactory.Evaluation`1.Complete(EvaluationResult2`1 result)
at Microsoft.Mashup.Evaluator.Interface.EvaluationResultExtensions.InvokeThenOnDispose(Action`1 callback, EvaluationResult2`1 result, Action action)
at Microsoft.Mashup.Evaluator.Interface.EvaluationResultExtensions.InvokeThenOnDispose[T](Action`1 callback, EvaluationResult2`1 result, Action action)
at Microsoft.Mashup.Evaluator.LimitedDocumentEvaluatorFactory.Evaluation`1.Complete(EvaluationResult2`1 result)
at Microsoft.Mashup.Evaluator.Interface.EvaluationResultExtensions.InvokeThenOnDispose(Action`1 callback, EvaluationResult2`1 result, Action action)
at Microsoft.Mashup.Evaluator.Interface.EvaluationResultExtensions.InvokeThenOnDispose[T](Action`1 callback, EvaluationResult2`1 result, Action action)
at Microsoft.Mashup.Evaluator.DocumentEvaluator.<>c__DisplayClass3`1.<BeginGetResult>b__0(EvaluationResult2`1 result)
at Microsoft.Mashup.Evaluator.Interface.EvaluationResultExtensions.InvokeThenOnDispose(Action`1 callback, EvaluationResult2`1 result, Action action)
at Microsoft.Mashup.Evaluator.Interface.EvaluationResultExtensions.InvokeThenOnDispose[T](Action`1 callback, EvaluationResult2`1 result, Action action)
at Microsoft.Mashup.Evaluator.LimitedDocumentEvaluatorFactory.Evaluation`1.Complete(EvaluationResult2`1 result)
at Microsoft.Mashup.Evaluator.RemoteDocumentEvaluator.RemoteEvaluation`1.TryComplete(EvaluationResult2`1 result)
at Microsoft.Mashup.Evaluator.RemoteDocumentEvaluator.PreviewValueSourceRemoteEvaluation.GetResult(Boolean enableFirewall)
at Microsoft.Mashup.Evaluator.RemoteDocumentEvaluator.RemoteEvaluation.Evaluate(Boolean enableFirewall)
at Microsoft.Mashup.Evaluator.EvaluatorThreadPool.EvaluatorThread(Object state)
at Microsoft.Mashup.Evaluator.SafeThread2.<>c__DisplayClass15.<CreateAction>b__14(Object o)
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(Object obj)
--- End of inner exception stack trace ---
at Microsoft.Mashup.Evaluator.EvaluationHost.OnException(IEngineHost engineHost, IMessageChannel channel, ExceptionMessage message)
at Microsoft.Mashup.Evaluator.MessageHandlers.TryDispatch(IMessageChannel channel, Message message)
at Microsoft.Mashup.Evaluator.MessageHandlers.Dispatch(IMessageChannel channel, Message message)
at Microsoft.Mashup.Evaluator.ChannelMessenger.ChannelMessageHandlers.TryDispatch(IMessageChannel channel, Message message)
at Microsoft.Mashup.Evaluator.MessageHandlers.Dispatch(IMessageChannel channel, Message message)
at Microsoft.Mashup.Evaluator.Interface.IMessageChannelExtensions.WaitFor[T](IMessageChannel channel)
at Microsoft.Mashup.EngineHost.Services.RemoteCredentialServiceFactory.Proxy.RefreshCredential(IResource resource, Boolean forceRefresh)
at Microsoft.Mashup.Engine1.Library.Http.OAuthCredentialExtensions.RefreshTokenAsNeeded(OAuthCredential credential, IEngineHost engineHost, IResource resource, Boolean forceRefresh)
at Microsoft.Mashup.Engine1.Library.Http.HttpResourceCredentialDispatcher.WebRequestCredentialDispatcher.ApplyOAuthCredential(OAuthCredential credential, Boolean useBase64Encoding)
at Microsoft.Mashup.Engine1.Library.Http.HttpResourceCredentialDispatcher.WebRequestCredentialDispatcher.Apply(OAuthCredential credential)
at Microsoft.Mashup.Engine1.Library.Http.HttpServices.ApplyCredentials(MashupHttpWebRequest httpRequest, String resourceKind, Uri requestUri, ResourceCredentialCollection credentials, IEngineHost hostEnvironment, String oAuthResource)
at Microsoft.Mashup.Engine1.Library.Web.HttpRequest.ApplyCredentialsToRequest(WebRequest webRequest, ResourceCredentialCollection credentials)
at Microsoft.Mashup.Engine1.Library.Web.Request.CreateWebRequest(Uri uri, ResourceCredentialCollection credentials)
at Microsoft.Mashup.Engine1.Library.Web.Request.CreateResponse(ResourceCredentialCollection credentials)
at Microsoft.Mashup.Engine1.Library.Web.Request.GetResponseCore(ResourceCredentialCollection credentials)
at Microsoft.Mashup.Engine1.Library.Common.RetryPolicy.Execute[TResult](IEngineHost host, Func`1 func)
at Microsoft.Mashup.Engine1.Library.Web.Request.GetResponse(ResourceCredentialCollection credentials, RetryPolicy retryPolicy, AuthorizationThrowFunction authorizationFunction, Boolean tokenRefreshed)
at Microsoft.Mashup.Engine1.Library.GoogleAnalytics.GoogleAnalyticsService.ExecuteRequest(UriBuilder uri)
at Microsoft.Mashup.Engine1.Library.GoogleAnalytics.GoogleAnalyticsService.GetReport(String viewId, GoogleAnalyticsQueryExpression compiledExpression)
at Microsoft.Mashup.Engine1.Library.GoogleAnalytics.GoogleAnalyticsCubeContextProvider.GoogleAnalyticsCubeContext.GoogleAnalyticsResultEnumerator.MoveNext()
at Microsoft.Mashup.Engine1.Library.GoogleAnalytics.GoogleAnalyticsCubeContextProvider.GoogleAnalyticsCubeContext.PagingResultEnumerator.MoveNext()
at Microsoft.Mashup.Evaluator.SimpleDocumentEvaluator.ValuePreviewValueSource.TableValuePreviewValueSource.SerializeRows(Int32 count)
at Microsoft.Mashup.Evaluator.SimpleDocumentEvaluator.ValuePreviewValueSource.TableValuePreviewValueSource.get_SmallValue()
at Microsoft.Mashup.Evaluator.Interface.TracingPreviewValueSource.get_SmallValue()
at Microsoft.Mashup.Evaluator.RemotePreviewValueSource.<>c__DisplayClass5.<RunStub>b__3()
at Microsoft.Mashup.Evaluator.EvaluationHost.ReportExceptions(IHostTrace trace, IEngineHost engineHost, IMessageChannel channel, Action action)
--- End of inner exception stack trace ---
at Microsoft.Mashup.Evaluator.EvaluationHost.<>c__DisplayClass7.<TryReportException>b__6()
at Microsoft.Mashup.Common.SafeExceptions.IgnoreSafeExceptions(IEngineHost host, IHostTrace trace, Action action)
at Microsoft.Mashup.Evaluator.EvaluationHost.TryReportException(IHostTrace trace, IEngineHost engineHost, IMessageChannel channel, Exception exception)
at Microsoft.Mashup.Evaluator.EvaluationHost.ReportExceptions(IHostTrace trace, IEngineHost engineHost, IMessageChannel channel, Action action)
at Microsoft.Mashup.Evaluator.RemotePreviewValueSource.RunStub(IEngineHost engineHost, IMessageChannel channel, Func`1 getPreviewValueSource)
at Microsoft.Mashup.Evaluator.RemoteDocumentEvaluator.Service.<>c__DisplayClass1e`1.<OnBeginGetResult>b__1b()
at Microsoft.Mashup.Evaluator.EvaluationHost.ReportExceptions(IHostTrace trace, IEngineHost engineHost, IMessageChannel channel, Action action)
at Microsoft.Mashup.Evaluator.RemoteDocumentEvaluator.Service.OnBeginGetResult[T](IMessageChannel channel, BeginGetResultMessage message, Action`1 action)
at Microsoft.Mashup.Evaluator.RemoteDocumentEvaluator.Service.OnBeginGetPreviewValueSource(IMessageChannel channel, BeginGetPreviewValueSourceMessage message)
at Microsoft.Mashup.Evaluator.MessageHandlers.TryDispatch(IMessageChannel channel, Message message)
at Microsoft.Mashup.Evaluator.ChannelMessenger.ChannelMessageHandlers.TryDispatch(IMessageChannel channel, Message message)
at Microsoft.Mashup.Evaluator.MessageHandlers.Dispatch(IMessageChannel channel, Message message)
at Microsoft.Mashup.Evaluator.ChannelMessenger.OnMessageWithUnknownChannel(IMessageChannel baseChannel, MessageWithUnknownChannel messageWithUnknownChannel)
at Microsoft.Mashup.Evaluator.MessageHandlers.TryDispatch(IMessageChannel channel, Message message)
at Microsoft.Mashup.Evaluator.ChannelMessenger.ChannelMessageHandlers.TryDispatch(IMessageChannel channel, Message message)
at Microsoft.Mashup.Evaluator.MessageHandlers.Dispatch(IMessageChannel channel, Message message)
at Microsoft.Mashup.Evaluator.EvaluationHost.Run()
at Microsoft.Mashup.Evaluator.SafeThread2.<>c__DisplayClass15.<CreateAction>b__14(Object o)
at Microsoft.Mashup.Container.EvaluationContainerMain.SafeRun(String[] args)
at Microsoft.Mashup.Container.EvaluationContainerMain.Main(String[] args)
--- End of inner exception stack trace ---
at Microsoft.Mashup.Evaluator.EvaluationHost.OnException(IEngineHost engineHost, IMessageChannel channel, ExceptionMessage message)
at Microsoft.Mashup.Evaluator.MessageHandlers.TryDispatch(IMessageChannel channel, Message message)
at Microsoft.Mashup.Evaluator.MessageHandlers.Dispatch(IMessageChannel channel, Message message)
at Microsoft.Mashup.Evaluator.ChannelMessenger.ChannelMessageHandlers.TryDispatch(IMessageChannel channel, Message message)
at Microsoft.Mashup.Evaluator.MessageHandlers.Dispatch(IMessageChannel channel, Message message)
at Microsoft.Mashup.Evaluator.Interface.IMessageChannelExtensions.WaitFor[T](IMessageChannel channel)
at Microsoft.Mashup.Evaluator.RemotePreviewValueSource.PreviewValueSource.WaitFor(Func`1 condition, Boolean disposing)
at Microsoft.Mashup.Evaluator.RemotePreviewValueSource.PreviewValueSource.get_SmallValue()
at Microsoft.Mashup.Evaluator.Interface.TracingPreviewValueSource.get_SmallValue()
at Microsoft.Mashup.Host.Document.Analysis.PackageDocumentAnalysisInfo.PackagePartitionAnalysisInfo.SetPreviewValue(EvaluationResult2`1 result, Func`1 getStaleSince, Func`1 getSampled)

OS Version:
Microsoft Windows NT 10.0.14393.0 (x64 en-US)

CLR Version:
4.7 or later [Release Number = 461814]

Peak Virtual Memory:
34.2 GB

Private Memory:
469 MB

Peak Working Set:
610 MB

IE Version:
11.2608.14393.0

User ID:
a1689805-88ed-46b0-8252-4cd911319145

Workbook Package Info:
1* - en-US, Query Groups: 0, fastCombine: Disabled, runBackgroundAnalysis: True.

Telemetry Enabled:
True

Model Default Mode:
Import

Snapshot Trace Logs:
C:\Users\MonguNi\AppData\Local\Microsoft\Power BI Desktop\FrownSnapShot2061685611.zip

Disabled Preview Features:
PBI_shapeMapVisualEnabled
MIntellisense
PBI_SpanishLinguisticsEnabled
PBI_PdfImport
PBI_ColumnProfiling
PBI_variationUIChange
PBI_PythonSupportEnabled
PBI_showIncrementalRefreshPolicy
PBI_showManageAggregations
PBI_FuzzyMatching
PBI_EnableWebDiagramView
PBI_improvedFilterExperience

Disabled DirectQuery Options:
PBI_DirectQuery_Unrestricted
TreatHanaAsRelationalSource

Cloud:
GlobalCloud

DPI Scale:
100%

Supported Services:
Power BI

[v-qiuyu-msft]

Hi @monguso13,

Which action do you perform in Power BI desktop then causes the issue occurs? 

There is a known issue that “Collection was modified; enumeration operation may not execute” error throws when we use Google Analytics connector to get data. The workaround is to clear Google Analytics credential. The fix will be available in Power BI desktop December version. See: https://community.powerbi.com/t5/Issues/Google-Analytics-Connector-in-PowerBI-Desktop/idi-p/566140/p...

Best Regards,
Qiuyun Yu 

[SergeiStPete]

I have exactly the same trying to connect to SPO folder, like

Source= SharePoint.Files("siteURL", [ApiVersion = 15])

Above is root URL

[v-qiuyu-msft]

Hi @SergeiStPete,

Do you mean the same issue occurs when you get data from SharePoint online folder? 

Please try the latest Power BI desktop version and clear credential cache then test it again. 

Best Regards,
Qiuyun Yu 

[Ehren]

Hi @monguso13 and @SergeiStPete. If you're still seeing the "Collection was modified" error even after upgrading to the December release, please let me know.

Thanks,

Ehren