Hello. I am receiving a "Sequence contains no elements" in an already translated file. I have searched the community here, but found no answer. Can you help me please? This is a big and urgent translation project that I have to finish today. Thank you!

Here is the detailed text of the error message: 

<SDLErrorDetails time="22. 12. 2020 15:11:38">
<ErrorMessage>Sequence contains no elements</ErrorMessage>
<Exception>
<Type>System.InvalidOperationException, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</Type>
<HelpLink />
<Source>System.Core</Source>
<HResult>-2146233079</HResult>
<StackTrace><
at Sdl.ProjectApi.Helpers.ConfirmationLevelStatisticsProcessor.ProcessParagraphUnit(IParagraphUnit paragraphUnit)
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.BilingualApi.AbstractBilingualContentProcessor.ProcessParagraphUnit(IParagraphUnit paragraphUnit)
at Sdl.FileTypeSupport.Filters.Processors.SegmentRenumberingBilingualProcessor.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.OnTranslationUnit(XmlElement translationUnit)
at Sdl.FileTypeSupport.Bilingual.SdlXliff.SdlXliffFeeder.<ContinueScanning>b__14_12(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.TranslationStudio.Editor.TranslationEditor.TranslatableDocument.Load(IJobExecutionContext context)
at Sdl.Desktop.Platform.Services.JobRequest.Execute(IJobExecutionContext context)
at Sdl.Desktop.Platform.Implementation.Services.Job.<_worker_DoWork>b__47_0()
at Sdl.Desktop.Logger.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)]]></StackTrace>
</Exception>
<Environment>
<ProductName>SDL Trados Studio</ProductName>
<ProductVersion>Studio16</ProductVersion>
<EntryAssemblyFileVersion>16.0.2.3343</EntryAssemblyFileVersion>
<OperatingSystem>Microsoft Windows 7 Home Premium </OperatingSystem>
<ServicePack>Service Pack 1</ServicePack>
<OperatingSystemLanguage>1051</OperatingSystemLanguage>
<CodePage>1250</CodePage>
<LoggedOnUser>RS-PC\RS</LoggedOnUser>
<DotNetFrameWork>4.0.30319.42000</DotNetFrameWork>
<ComputerName>RS-PC</ComputerName>
<ConnectedToNetwork>True</ConnectedToNetwork>
<PhysicalMemory>8073084 MB</PhysicalMemory>
</Environment>
</SDLErrorDetails>