This is the error script I get. I understand many people have got problems with Saving file as target, I keep on getting the same problem with XLS; it had never happened before these last few days and I wish I knew why. Help anybody? Kind regards.

Fullscreen errorstack.xml Download

<?xml version="1.0"?>
<SDLErrorDetails time="07/09/2017 10:13:54">
<ErrorMessage>Failed to save target content: Object reference not set to an instance of an object.</ErrorMessage>
<Exception>
<Type>System.NullReferenceException, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</Type>
<HelpLink/>
<Source>Sdl.FileTypeSupport.Filters.Excel</Source>
<HResult>-2147467261</HResult>
<StackTrace>
<![CDATA[
   at Sdl.FileTypeSupport.Filters.Excel.FilterControllerFramework.OfficeController.UpdateDocumentFile(XsltArgumentList argsList, XslCompiledTransform xslTransform, XPathNavigator child)
   at Sdl.FileTypeSupport.Filters.Excel.FilterControllerFramework.OfficeController.IterateXsltFiles(XsltArgumentList argsList, FileMap rule, XPathNodeIterator iter, Boolean isUpdate, String targetFilePath)
   at Sdl.FileTypeSupport.Filters.Excel.FilterControllerFramework.OfficeController.IterateContentType(String xslFileNamesPath, Boolean isUpdate, String filePath, String filterStr, String targetFilePath, Boolean isCalledByRelsTableIteration)
   at Sdl.FileTypeSupport.Filters.Excel.FilterControllerFramework.OfficeController.serviceBackward()
   at Sdl.FileTypeSupport.Filters.Excel.PlugInFilter.FileParser.DocumentParser.Update()
   at Sdl.FileTypeSupport.Filters.Excel.PlugInFilter.FileParser.DocumentExtractImpl.Update(DocumentCollection srcCollection, String filename, String tgtFilePath)
   at Sdl.FileTypeSupport.Filters.Excel.PlugInFilter.FileWriterAndPreviewFileWriter.WriterImpl.EndOfInput()
   at Sdl.FileTypeSupport.Filters.Excel.PlugInFilter.FileWriterAndPreviewFileWriter.ExcelWriter.EndOfInput()
   at Sdl.FileTypeSupport.Framework.Integration.NativeWriterMessagesProxy.EndOfInput()
   at Sdl.FileTypeSupport.Framework.Integration.FileGenerator.CallEndOfInput()
   at Sdl.FileTypeSupport.Framework.Integration.FileGenerator.FileComplete()
   at Sdl.FileTypeSupport.Framework.Integration.AbstractBilingualProcessorContainer.FileComplete()
   at Sdl.FileTypeSupport.Framework.Integration.MultiFileConverter.FileComplete()
   at Sdl.FileTypeSupport.Framework.BilingualApi.AbstractBilingualContentProcessor.FileComplete()
   at Sdl.FileTypeSupport.Framework.Integration.AbstractBilingualProcessorContainer.FileComplete()
   at Sdl.FileTypeSupport.Bilingual.Tmfc.TmfcReaderImpl.vv_Visit(TmfcReaderImpl* , FrameworkFileContainerField* field)
   at FrameworkFileContainerField.vv_AcceptFrameworkVisitor(FrameworkFileContainerField* , FrameworkFieldVisitor* visitor)
   at Sdl.FileTypeSupport.Bilingual.Tmfc.TmfcReaderImpl.vv_VisitStartEndField(TmfcReaderImpl* , StartEndField* startEnd)
   at Sdl.FileTypeSupport.Bilingual.Tmfc.TmfcReaderImpl.b_VisitNext(TmfcReaderImpl* )
   at Sdl.FileTypeSupport.Bilingual.Tmfc.TmfcReader.ParseNext()
   at Sdl.FileTypeSupport.Framework.Integration.FileExtractor.ParseNext()
   at Sdl.FileTypeSupport.Framework.Integration.MultiFileConverter.ParseNext()
   at Sdl.FileTypeSupport.Framework.Integration.MultiFileConverter.Parse()
   at Sdl.TranslationStudio.Editor.TranslationEditor.TranslatableDocument.SaveMonolingualAsJobRequest.Execute(IJobExecutionContext context)
   at Sdl.Desktop.Platform.Implementation.Services.Job.<_worker_DoWork>b__3()
   at Sdl.Desktop.Platform.Implementation.Services.Log.Resources(Object message, Action action)
   at Sdl.Desktop.Platform.Implementation.Services.Job._worker_DoWork(Object sender, DoWorkEventArgs e)
   at System.ComponentModel.BackgroundWorker.OnDoWork(DoWorkEventArgs e)
   at System.ComponentModel.BackgroundWorker.WorkerThreadStart(Object argument)