I am working on a huge project with more than 200 files and everytime I open many files together I get this error message and it prevents me from saving the segments to the TM.

<SDLErrorDetails time="25/01/2019 11:31:09">
<ErrorMessage>O índice estava fora do intervalo. Ele deve ser não-negativo e menor que o tamanho da coleção.
Nome do parâmetro: index</ErrorMessage>
<Exception>
<Type>System.ArgumentOutOfRangeException, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</Type>
<ParamName>index</ParamName>
<HelpLink />
<Source>mscorlib</Source>
<HResult>-2146233086</HResult>
<StackTrace><![CDATA[ em System.ThrowHelper.ThrowArgumentOutOfRangeException(ExceptionArgument argument, ExceptionResource resource)
em Sdl.TranslationStudio.Editor.TranslationMemory.TranslationMemoryViewPartControl.ShowDocumentSource(List`1 placeables, EditDistance editDistanceInformation, Segment tuSourceSegment, Segment tokenizedDocumentSourceSegment)
em Sdl.TranslationStudio.Editor.TranslationMemory.TranslationMemoryViewPartControl.ShowDocumentSource()
em Sdl.TranslationStudio.Editor.TranslationMemory.TranslationMemoryViewPartControl.TranslationMemoryViewPartControl_CurrentSearchResultChanged(Object sender, EventArgs e)
em System.EventHandler.Invoke(Object sender, EventArgs e)
em Sdl.TranslationStudio.Editor.TranslationMemory.CompoundTranslationMemorySearchResultsControl._searchResultsControl_CurrentTranslationUnitChanged(Object sender, EventArgs e)
em Sdl.TranslationStudio.Common.TranslationMemory.AbstractTranslationMemoryControl`1.OnCurrentTranslationUnitChanged()
em Sdl.TranslationStudio.Common.TranslationMemory.AbstractTranslationMemoryControl`1.HandleActiveRowChanged(ActiveRowChangedEventArgs e)
em Sdl.TranslationStudio.Common.TranslationMemory.AbstractTranslationMemoryControl`1.Source_ActiveRowChanged(Object sender, ActiveRowChangedEventArgs e)
em System.EventHandler`1.Invoke(Object sender, TEventArgs e)
em AbstractFrameworkEditControl.raise_ActiveRowChanged(Object value0, ActiveRowChangedEventArgs value1)
em AbstractFrameworkEditControl.OnActiveRowChanged(Object sender, ActiveRowChangedEventArgs args)
em AbstractFrameworkEditControl.set_ActiveRow(IRowInfo activeRow)
em Sdl.DesktopEditor.Control.Support.RowInfo.set_Active(Boolean value)
em SideBySideEditor.set_ActiveRowNumber(Int32 rowNumber)
em Sdl.TranslationStudio.Common.TranslationMemory.AbstractTranslationMemoryControl`1.set_CurrentTranslationUnitIndex(Int32 value)
em Sdl.TranslationStudio.Common.TranslationMemory.AbstractTranslationMemoryControl`1.SideBySideEditor_AfterInitialUpdate(Object sender, AfterInitialUpdateEventArgs e)
em SideBySideEditor.raise_AfterInitialUpdate(Object value0, AfterInitialUpdateEventArgs value1)
em SideBySideEditor.OnAfterInitialUpdate(Object sender, AfterInitialUpdateEventArgs args)
em SideBySideEditor.Target_AfterInitialUpdate(Object sender, AfterInitialUpdateEventArgs args)
em AbstractFrameworkEditControl.raise_AfterInitialUpdate(Object value0, AfterInitialUpdateEventArgs value1)
em AbstractFrameworkEditControl.OnAfterInitialUpdate(Object sender, AfterInitialUpdateEventArgs args)
em FrameworkEditControlEventSource.AfterInitialUpdate(FrameworkEditControlEventSource* )
em Tree.DocumentControl.vl_WindowProc(DocumentControl* , HWND__* , UInt32 , UInt32 , Int32 )
em FrameworkDocumentControl.vl_WindowProc(FrameworkDocumentControl* , HWND__* h_wnd, UInt32 n_msg, UInt32 w_p, Int32 l_p)
em System.Windows.Forms.UnsafeNativeMethods.CallWindowProc(IntPtr wndProc, IntPtr hWnd, Int32 msg, IntPtr wParam, IntPtr lParam)
em System.Windows.Forms.NativeWindow.DefWndProc(Message& m)
em System.Windows.Forms.Control.DefWndProc(Message& m)
em System.Windows.Forms.Control.WndProc(Message& m)
em System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
em System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
em System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)]]></StackTrace>
</Exception>
<Environment>
<ProductName>SDL Trados Studio</ProductName>
<ProductVersion>12.0.0.0</ProductVersion>
<EntryAssemblyFileVersion>12.3.5281.10</EntryAssemblyFileVersion>
<OperatingSystem>Microsoft Windows 10 Pro</OperatingSystem>
<ServicePack>NULL</ServicePack>
<OperatingSystemLanguage>1046</OperatingSystemLanguage>
<CodePage>1252</CodePage>
<LoggedOnUser>ELIS-EST\Elis</LoggedOnUser>
<DotNetFrameWork>4.0.30319.42000</DotNetFrameWork>
<ComputerName>ELIS-EST</ComputerName>
<ConnectedToNetwork>True</ConnectedToNetwork>
<PhysicalMemory>8081940 MB</PhysicalMemory>
</Environment>
</SDLErrorDetails>