the given key is not present in dictionary - power query load into power BI

[Anonymous]

I am trying to load 45,000 rows of data from 5 separate files appended into a single file in power BI? Is the file size the problem? I copy and pasted the same data transformations to each file and was given this error, I have never seen this before. Does anyone know how to fix? Below are some details that i copied from the clipboard if they help at all. 

Stack Trace:
System.Collections.Generic.KeyNotFoundException
at System.ThrowHelper.ThrowKeyNotFoundException()
at System.Collections.Generic.Dictionary`2.get_Item(TKey key)
at Microsoft.PowerBI.Client.Windows.Modeling.LoadToReportProgress.UpdateImportProgressProviders(IPowerBITrace trace)
at Microsoft.PowerBI.Client.Windows.Modeling.LoadToReportProgress.<UpdateImportProgress>b__23_0()
at Microsoft.Mashup.Host.Document.ExceptionHandlerExtensions.HandleExceptions(IExceptionHandler exceptionHandler, Action action)

PowerBINonFatalError:
{"AppName":"PBIDesktop","AppVersion":"2.115.1006.0","ModuleName":"Microsoft.PowerBI.Client.Windows.dll","Component":"Microsoft.PowerBI.Client.Windows.Modeling.LoadToReportProgress","Error":"System.Collections.Generic.KeyNotFoundException","MethodDef":"UpdateImportProgressProviders","ErrorOffset":"78"}

[v-yanjiang-msft]

Hi @Anonymous ,

To dig if the file size is the problem, please try to append just 2 or 3 files to see if any error occurs. Additionally, what's the connection mode of the file? For import mode, the limit of model size is 1GB. If it still not help, please try to collect diagnostic trace to see if there're any detailed error information.

Best regards,

Community Support Team_yanjiang