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Error: A module named 'AtScale' hasn't been loaded


I got this today when I tried to reopen a pbix file:

A module named 'AtScale' hasn't been loaded.


Today I downloaded the latest Power BI Desktop (Version: 2.66.5376.2521 64-bit (February, 2019)), and created this report using that version. I reopened the solution and get the above error. I have included the trace.


thanks for the help!


Feedback Type:
Frown (Error)


Local Time:

Session ID:

February, 2019

Product Version:
2.66.5376.2521 (19.02) (x64)

Stack Trace:
at Microsoft.Mashup.Engine1.Language.LanguageLibrary.GetLibrary(IEngineHost host, IEnumerable`1 additionalModules)
at Microsoft.Mashup.Host.Document.DataSourceDiscovery.DataSourceDiscoveryVisitor.get_CurrentLibrary()
at Microsoft.Mashup.Host.Document.DataSourceDiscovery.DataSourceDiscoveryVisitor..ctor(HashSet`1 moduleMemberFilter)
at Microsoft.Mashup.Host.Document.DataSourceDiscovery.DataSourceDiscoveryVisitor.FindDataSources(IEnumerable`1 documents, HashSet`1 moduleMemberFilter)
at Microsoft.PowerBI.Client.Windows.PowerBIQueryExtensions.DiscoverUniqueMashupSource(IEnumerable`1 queries, String& sourceType, Resource& resource)
at Microsoft.PowerBI.Client.Windows.DirectQueryImportProcessor.TryGetUniqueDirectQueryResource(IEnumerable`1 queries, Resource& resource)
at Microsoft.PowerBI.Client.Windows.DirectQueryImportProcessor.GetCoexistenceStatus(IEnumerable`1 queries)
at Microsoft.PowerBI.Client.Windows.Modeling.StorageModeHelpers.ShouldShowCompositeModelSecurityWarning(Report report, IEnumerable`1 queriesToLoad)
at Microsoft.PowerBI.Client.Windows.Modeling.StorageModeHelpers.CheckCompositeModelsSecurityFlag(Report report, IEnumerable`1 queriesToLoad, IPowerBITelemetryService telemetryService, IPowerBIWindowService windowService, IUIBlockingService uiBlockingService, Boolean onFileOpen)
at Microsoft.PowerBI.Client.Windows.ReportPreparer.EnsureCompositeModelSecurityFlag(Report report, IPowerBIWindowService windowService)
at Microsoft.PowerBI.Client.Windows.ReportPreparer.Prepare(Report report, PackageValidationResult mashupResult, IPowerBIWindowService windowService, Nullable`1 entryPoint)
at Microsoft.PowerBI.Client.Windows.Services.PowerBIPackagingService.Open(FileStream fileStream, IPowerBIWindowService windowService, Nullable`1 entryPoint, PowerBIPackageOpenOptions options, ReportPreparerResult& prepareResult)
at Microsoft.PowerBI.Client.Windows.Services.FileManager.<LoadFromPbix>d__19.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at Microsoft.PowerBI.Client.Windows.Services.UIBlockingService.<>c__DisplayClass15_0`1.<<BlockUIAndRun>b__0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at Microsoft.PowerBI.Client.Windows.Services.UIBlockingService.WaitOnUIThreadForTaskCompletion(Task task)
at Microsoft.PowerBI.Client.Windows.Services.UIBlockingService.BlockUIAndRun[T](Func`1 asyncMethod)
at Microsoft.PowerBI.Client.Windows.Services.FileManager.OpenFile(IPowerBIWindowService windowService, IPbixFile fileToOpen, Nullable`1 entryPoint)
at Microsoft.PowerBI.Client.Program.TryOpenOrCreateReport(IUIHost uiHost, ISplashScreen splashScreen, IFileManager fileManager, IFileHistoryManager fileHistoryManager, String filePath, FileType fileType)
at Microsoft.PowerBI.Client.Program.<>c__DisplayClass4_0.<Main>b__1()
at Microsoft.PowerBI.Client.Windows.IExceptionHandlerExtensions.<>c__DisplayClass3_0.<HandleExceptionsWithNestedTasks>b__0()
at Microsoft.Mashup.Host.Document.ExceptionHandlerExtensions.HandleExceptions(IExceptionHandler exceptionHandler, Action action)

OS Version:
Microsoft Windows NT 6.1.7601 Service Pack 1 (x64 en-US)

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

Peak Virtual Memory:
3.39 GB

Private Memory:
200 MB

Peak Working Set:
264 MB

IE Version:

User ID:

Telemetry Enabled:

DPI Scale:

Supported Services:
Power BI

Status: Needs Info
Community Support

Hi @lakesidecoder ,


Which data source do you get data from and which connection mode do you use? 


Does the same issue occur when you open other pbix file which is created by the same Power BI desktop version. 


Best Regards,
Qiuyun Yu 

Community Support
Status changed to: Needs Info
Regular Visitor

Hi, I don't have any issues with other power bi reports that I created before or after I upgraded. My data connections all are sql server direct query.  The visuals are all outofthebox plus the Text filter one in the marketplace.



Regular Visitor

ooh I think just figured out what is causing it. I have another report, working well.

  1. I just changed the y-axis "display units" property on a line chart from "Auto" to "Thousands". Works on the report, shows the change.
  2. save and close the report.
  3. reopen the report.
  4. error.
Community Support

Hi @lakesidecoder,


I have created a line chart displaying data from one SQL database table in Directquery mode, follow your steps but not able to reproduce the issue in Power BI 2.66.5376.2521 64-bit (February 2019). 


In your scenario, does the line chart display data from one table or multiple tables? How about the result if there is only one table? 


Best Regards,
Qiuyun Yu 

Regular Visitor

Hi Qiuyun,

I have had intermittent success today at causing the failure. I got it to fail once out of 5 attempts. 

  • I reopen the report/PBI desktop by double-clicking the PBIX file
  • The report has 5 tables, but this chart only uses data from one of them. 
  • today my report seems slower in loading the data, maybe that is a factor
  • I have attached a couple of screen shots so you can see the magnitude of the scale and the amount of data
  • after scale changeafter scale changeBefore scale changeBefore scale change

Thank you for your help!

Community Support

Hi @lakesidecoder


It look like the error "A module named 'AtScale' hasn't been loaded" still occurs when you reopen the report, right? I would suggest you create a support ticket to let engineers look into the issue on your side. 


Support Ticket.gif


Best Regards,
Qiuyun Yu 

Not applicable

One of my staff is also experiencing this issue upon upgrading from the December release to the March one. It is fine on my desktop where I still have December installed.


Has there been any progress fixing this? Or a workaround?

Frequent Visitor

I am also getting this more and more frequently.


Connecting to Azure SQL, DirerctQuery.


Various reports. There seems to be no obvious pattern to the error.

Regular Visitor

Having the same issue.  A workaround seems to be:

1. First open PowerBI desktop

2. Open your pbix file from within a running PBI Desktop