Unexpected Error - operation not valid when running Folder.Contents

I'm experiencing an error on a PBIX file that has previously functioned.

The query I'm running is simply:

let
Source = Folder.Contents("\\networkfolder\Power_BI\DashBoard\Data")
in
    Source

I've tried recreating this query in a new PBIX file and it still produces the same error.

The error logs as captured are included below.

Feedback Type:
Frown (Error)

Timestamp:
2019-06-04T20:14:58.0813609Z

Local Time:
2019-06-05T05:44:58.0813609+09:30

Session ID:
83c7a15e-5abd-419e-86be-18ea01dfa796

Release:
May 2019

Product Version:
2.69.5467.2151 (19.05) (x64)

Stack Trace:
Microsoft.Mashup.Evaluator.Interface.ErrorException: Operation is not valid due to the current state of the object. ---> System.InvalidOperationException: Operation is not valid due to the current state of the object. ---> System.InvalidOperationException: Operation is not valid due to the current state of the object.
at Microsoft.Mashup.Engine1.Library.File.FileHelper.GetAccessControlEntries(AccessControlEntriesCache cache, String fullName, Boolean directory, FileSystemRights rights)
at Microsoft.Mashup.Engine1.Runtime.RecordValue.DemandRecordValue.get_Item(Int32 index)
at Microsoft.Mashup.Evaluator.Services.ValueSerializer.<>c__DisplayClass68_0.<WriteMetaField>b__0()
at Microsoft.Mashup.Evaluator.Services.ValueSerializer.HandleErrors(Action action, Action`1 handler)
at Microsoft.Mashup.Evaluator.Services.ValueSerializer.WriteMetaRecord(IRecordValue value, Boolean truncatedValue)
at Microsoft.Mashup.Evaluator.Services.ValueSerializer.WriteValueEnd(IValue value, IRecordValue meta, Boolean truncated)
at Microsoft.Mashup.Evaluator.Services.ValueSerializer.WriteLimitedValue(IValue value)
at Microsoft.Mashup.Evaluator.Services.ValueSerializer.<>c__DisplayClass108_0.<WritePreviewFieldValue>b__0()
at Microsoft.Mashup.Evaluator.Services.ValueSerializer.HandleErrors(Action action, Action`1 handler)
at Microsoft.Mashup.Evaluator.Services.ValueSerializer.<>c__DisplayClass99_2.<WritePreviewTable>b__2()
at Microsoft.Mashup.Evaluator.Services.ValueSerializer.HandleErrors(Action action, Action`1 handler)
at Microsoft.Mashup.Evaluator.Services.ValueSerializer.<>c__DisplayClass99_1.<WritePreviewTable>b__1()
at Microsoft.Mashup.Evaluator.Services.ValueSerializer.HandleErrors(Action action, Action`1 handler)
at Microsoft.Mashup.Evaluator.Services.ValueSerializer.HandleErrors(Action action, Action`1 handler)
at Microsoft.Mashup.Evaluator.Services.ValueSerializer.WritePreviewTable(IValue value)
at Microsoft.Mashup.Evaluator.Services.ValueSerializer.HandleErrors(Action action, Action`1 handler)
at Microsoft.Mashup.Evaluator.Services.ValueSerializer.WritePreviewValue(IValue value, Int32 serializeStructuredValueDepth)
at Microsoft.Mashup.Evaluator.Services.ValueSerializer.SerializePreviewValue(IEngine engine, IValue value, Action`2 rowCountCallback, Nullable`1 options)
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__DisplayClass0_0.<RunStub>b__0()
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__DisplayClass11_0.<TryReportException>b__1()
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__DisplayClass12_1`1.<OnBeginGetResult>b__0()
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.Container.EvaluationContainerMain.Run(Object args)
at Microsoft.Mashup.Evaluator.SafeThread2.<>c__DisplayClass9_0.<CreateAction>b__0(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 10.0.18362.0 (x64 en-GB)

CLR Version:
4.7 or later [Release Number = 528040]

Peak Virtual Memory:
39.5 GB

Private Memory:
1.03 GB

Peak Working Set:
1.31 GB

IE Version:
11.113.18362.0

User ID:
8d8480ec-a839-477e-bae9-e32817b8da9e

Workbook Package Info:
1* - en-AU, Query Groups: 1, fastCombine: Enabled, runBackgroundAnalysis: False.

Telemetry Enabled:
True

Model Default Mode:
Import

Snapshot Trace Logs:
C:\Users\xxxxx\Microsoft\Power BI Desktop Store App\FrownSnapShot570451135.zip

Disabled Preview Features:
PBI_shapeMapVisualEnabled
PBI_SpanishLinguisticsEnabled
PBI_NewWebTableInference
PBI_showIncrementalRefreshPolicy
PBI_showManageAggregations
PBI_improvedFilterExperience
PBI_qnaLiveConnect
PBI_keyDrivers

Disabled DirectQuery Options:
TreatHanaAsRelationalSource

Cloud:
GlobalCloud

DPI Scale:
125%

Supported Services:
Power BI