2020R1(S1):Receipt Advice - Investigate processing an import for an 'on hold' order

Environment: JAT
Build: CFA - 20.1.0.2574
Store: 01640 - St. Johns Town Center FSU
User: System Admin
Day: Tue, Sep 26th, 2019

Received This in the log when importing the attached file for an order that is 'on hold'.

Task threw exception System.IO.IOException: The process cannot access the file 'W:\MacromatiX\SiteData\JATesting\DataImports\ReceiptAdvice\Logs\ReceiptAdviceImportLog_20190926_131251.log' because it is being used by another process.
at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
at System.IO.FileStream.Init(String path, FileMode mode, FileAccess access, Int32 rights, Boolean useRights, FileShare share, Int32 bufferSize, FileOptions options, SECURITY_ATTRIBUTES secAttrs, String msgPath, Boolean bFromProxy)
at System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, FileOptions options, String msgPath, Boolean bFromProxy)
at System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, FileOptions options)
at System.IO.StreamWriter..ctor(String path, Boolean append, Encoding encoding, Int32 bufferSize)
at System.IO.StreamWriter..ctor(String path, Boolean append)
at System.IO.File.AppendText(String path)
at MMS.Tasks.MMSTasks.TaskDataImport.AppendAuditLog()
at MMS.Tasks.MMSTasks.TaskDataImport.ProcessTask()
Event : 9/26/2019 5:14:40 PM : Receipt Advice Import Data Import on 9/26/2019 5:14:40 PM : Starting Data Import
Event : 9/26/2019 5:14:40 PM : Data Import on 9/26/2019 5:14:40 PM : Source File W:\MacromatiX\SiteData\JATesting\DataImports\ReceiptAdvice\902_2104809_QCD.xml successfully validated
Task threw exception System.ArgumentNullException: Value cannot be null.
Parameter name: source
at System.Linq.Enumerable.First[TSource](IEnumerable`1 source)
at Mx.Services.ReceiptAdviceImportProvider.NotificationSystemSubject(DataImportClassSet importClassSet, IImportSourceProvider importSource, Int32 numberOfImportRecords, AutoNotificationType noticeType, Dictionary`2 importRecordDictionary)
at Mx.Services.ImportService.GenerateAutoNotifications(DataImportClassSet importClassSet, IImportSourceProvider importSource, Dictionary`2 importRecordDictionary, AutoNotificationType noticeType, DataImportTask dataImportTask, BusinessUser executingUser, String message)
at Mx.Services.ImportService.Import(DataImportClassSet importClassSet, IImportSourceProvider importSource, ImportLoggingLevel logLevel, ITaskController taskController, DataImportTask dataImportTask, BusinessUser executingUser, List`1 newSourceFilePaths, List`1 importLog)
at Mx.Services.ImportService.ImportFromSource(String sourceFile, DataImportClassSet importClassSet, List`1& importLog)
at Mx.Services.ImportService.ExecuteDataImport(List`1& importLog, String[] sourceFiles)
at MMS.Tasks.MMSTasks.TaskDataImport.ProcessTask()