I cannot import an XML file in Trados (Object reference not set to an instance of an object.)

Hi there,

I'm having an issue importing an XML file using the customer's own file type definition and DTDs. if I try to import this file, I get an "Object reference not set to an instance of an object.".
But if I try to import using the standard XML file type, I don't get any errors.

What can be the issue here? From the XML error message it seems to be a segmentation error, but I don't know what this could be due to, since the imported XML is valid.

I also tried to reinstall Trados, but it didn't help.

Here's the full error message:

<SDLErrorDetails time="10/05/2021 10:23:25">
  <ErrorMessage>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.Core.LanguageProcessing</Source>
    <HResult>-2147467261</HResult>
    <StackTrace><![CDATA[   at Sdl.Core.LanguageProcessing.Segmentation.SegmentationTreeManager.HandleStarterEnderGroupingsContainerSplits()
   at Sdl.Core.LanguageProcessing.Segmentation.SegmentationTreeManager.HandleContainerSplits()
   at Sdl.Core.LanguageProcessing.Segmentation.Segmentor.CreateSegments(IAbstractMarkupDataContainer content, SegmentorUtility segmentorUtility)
   at Sdl.Core.LanguageProcessing.Segmentation.Segmentor.ProcessParagraph(IAbstractMarkupDataContainer paragraph)
   at Sdl.Core.LanguageProcessing.Segmentation.Segmentor.ProcessParagraphUnit(IParagraphUnit transUnit)
   at Sdl.FileTypeSupport.Framework.Core.Utilities.BilingualApi.BilingualContentHandlerAdapter.ProcessParagraphUnit(IParagraphUnit paragraphUnit)
   at Sdl.FileTypeSupport.Framework.Core.Utilities.BilingualApi.BilingualContentHandlerAdapter.ProcessParagraphUnit(IParagraphUnit paragraphUnit)
   at Sdl.FileTypeSupport.Framework.Integration.AbstractBilingualProcessorContainer.ProcessParagraphUnit(IParagraphUnit paragraphUnit)
   at Sdl.FileTypeSupport.Framework.BilingualApi.AbstractBilingualContentProcessor.ProcessParagraphUnit(IParagraphUnit paragraphUnit)
   at Sdl.FileTypeSupport.Framework.Integration.LocationMarkerLocator.ProcessParagraphUnit(IParagraphUnit paragraphUnit)
   at Sdl.FileTypeSupport.Framework.Integration.AbstractBilingualProcessorContainer.ProcessParagraphUnit(IParagraphUnit paragraphUnit)
   at Sdl.FileTypeSupport.Framework.Integration.FileExtractor.ProcessParagraphUnit(IParagraphUnit paragraphUnit)
   at Sdl.FileTypeSupport.Framework.Core.Utilities.BilingualApi.ParagraphUnitBuffer.ProcessParagraphUnit(IParagraphUnit pu)
   at Sdl.FileTypeSupport.Bilingual.SdlXliff.XliffFileReader.OutputParagraphUnit(IParagraphUnit pu)
   at Sdl.FileTypeSupport.Bilingual.SdlXliff.XliffFileReader.ParseLocalizableParagraphUnit(transunit transunit, LockTypeFlags lockFlags)
   at Sdl.FileTypeSupport.Bilingual.SdlXliff.XliffFileReader.ParseTransUnit(transunit transunit)
   at Sdl.FileTypeSupport.Bilingual.SdlXliff.XliffFileReader.ParseGroup(group group)
   at Sdl.FileTypeSupport.Bilingual.SdlXliff.XliffFileReader.OnGroup(XmlElement groupElement)
   at Sdl.FileTypeSupport.Bilingual.SdlXliff.SdlXliffFeeder.<ContinueScanning>b__14_15(ISdlXliffStreamContentHandler handler)
   at System.Collections.Generic.List`1.ForEach(Action`1 action)
   at Sdl.FileTypeSupport.Bilingual.SdlXliff.SdlXliffFeeder.ContinueScanning()
   at Sdl.FileTypeSupport.Bilingual.SdlXliff.XliffFileReader.ContinueParsing()
   at Sdl.FileTypeSupport.Bilingual.SdlXliff.XliffFileReader.ParseNext()
   at Sdl.FileTypeSupport.Framework.Integration.FileExtractor.ParseNext()
   at Sdl.FileTypeSupport.Framework.Integration.MultiFileConverter.ParseNext()
   at Sdl.FileTypeSupport.Framework.Integration.MultiFileConverter.Parse()
   at Sdl.ProjectApi.Implementation.TaskExecution.ContentProcessingTaskImplementation.TaskFileExecuter.Parse(String targetFilePath)]]></StackTrace>
  </Exception>
  <Environment>
    <ProductName>SDL Trados Studio</ProductName>
    <ProductVersion>14.0.0.0</ProductVersion>
    <EntryAssemblyFileVersion>14.1.10018.54792</EntryAssemblyFileVersion>
    <OperatingSystem>Microsoft Windows Server 2008 R2 Standard </OperatingSystem>
    <ServicePack>Service Pack 1</ServicePack>
    <OperatingSystemLanguage>1040</OperatingSystemLanguage>
    <CodePage>1252</CodePage>
    <LoggedOnUser>e.giai</LoggedOnUser>
    <DotNetFrameWork>4.0.30319.42000</DotNetFrameWork>
    <ComputerName>RDP01</ComputerName>
    <ConnectedToNetwork>True</ConnectedToNetwork>
    <PhysicalMemory>25165304 MB</PhysicalMemory>
  </Environment>
</SDLErrorDetails>

What can I do?

Thanks a lot,
Enrico