"Object reference not set to an instance of an object" whenever I split a segment.

I get an error each time I split a segment. This is new. Can it be the InSource App?

"<Source>Sdl.TranslationStudioAutomation.IntegrationApi</Source>"

<SDLErrorDetails time="18-Dec-19 11:36:16">
  <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.TranslationStudioAutomation.IntegrationApi</Source>
    <HResult>-2147467261</HResult>
    <StackTrace><![CDATA[   at Sdl.TranslationStudioAutomation.IntegrationApi.Internal.Adaptors.SegmentExtensions.ToPublicSegmentPairClone(ISegment segment, ITranslatableDocument document)
   at Sdl.TranslationStudioAutomation.IntegrationApi.Document.GetActiveSegmentPair()
   at Sdl.TranslationStudioAutomation.IntegrationApi.Document.get_ActiveSegmentPair()
   at Sdl.Community.AdvancedDisplayFilter.Controls.DisplayFilterControl.ActiveDocument_ContentChanged(Object sender, DocumentContentEventArgs e)
   at Sdl.Desktop.Platform.Extensions.EventsExtensions.Raise[T](EventHandler`1 e, Object sender, T eventArgs)
   at Sdl.TranslationStudioAutomation.IntegrationApi.Document.OnTranslatableDocumentContentChanged(Object sender, TranslatableDocumentContentChangedEventArgs translatableDocumentContentChangedEventArgs)
   at System.EventHandler`1.Invoke(Object sender, TEventArgs e)
   at Sdl.TranslationStudio.Editor.TranslationEditor.TranslatableDocument.OnTranslatableDocumentContentChanged(ICollection`1 affectedSegments)
   at Sdl.TranslationStudio.Editor.TranslationEditor.TranslatableDocument.HandleTargetContentChanged(FrameworkDocumentContentChangedEventArgs args)
   at Sdl.TranslationStudio.Editor.TranslationEditor.TranslatableDocument.Target_ContentChanged(Object sender, FrameworkDocumentContentChangedEventArgs args)
   at System.EventHandler`1.Invoke(Object sender, TEventArgs e)
   at AbstractFrameworkDocument.raise_ContentChanged(Object value0, FrameworkDocumentContentChangedEventArgs value1)
   at AbstractFrameworkDocument.OnContentChanged(Object sender, FrameworkDocumentContentChangedEventArgs args)
   at FrameworkDocumentEventSource.RaiseContentChanged(FrameworkDocumentEventSource* )
   at FrameworkDocumentEventSource.vv_AfterCompositeCommandCompleted(FrameworkDocumentEventSource* )
   at Tree.Commander.v_EndCompositeCommand(Commander* )
   at Tree.CompositeCommandCaller.__delDtor(CompositeCommandCaller* , UInt32 A_0)
   at FilterFramework.Ptr<Tree::CompositeCommandCaller>.{dtor}(Ptr<Tree::CompositeCommandCaller>* )
   at FilterFramework.Ptr<Tree::CompositeCommandCaller>.__vecDelDtor(Ptr<Tree::CompositeCommandCaller>* , UInt32 A_0)
   at std._List_buy<FilterFramework::Ptr<Tree::CompositeCommandCaller>,std::allocator<FilterFramework::Ptr<Tree::CompositeCommandCaller> > >._Freenode(_List_buy<FilterFramework::Ptr<Tree::CompositeCommandCaller>\,std::allocator<FilterFramework::Ptr<Tree::CompositeCommandCaller> > >* , _List_node<FilterFramework::Ptr<Tree::CompositeCommandCaller>\,void \*>* _Pnode)
   at std.list<FilterFramework::Ptr<Tree::CompositeCommandCaller>,std::allocator<FilterFramework::Ptr<Tree::CompositeCommandCaller> > >.clear(list<FilterFramework::Ptr<Tree::CompositeCommandCaller>\,std::allocator<FilterFramework::Ptr<Tree::CompositeCommandCaller> > >* )
   at std._List_buy<std::list<FilterFramework::Ptr<Tree::CompositeCommandCaller>,std::allocator<FilterFramework::Ptr<Tree::CompositeCommandCaller> > >,std::allocator<std::list<FilterFramework::Ptr<Tree::CompositeCommandCaller>,std::allocator<FilterFramework::Ptr<Tree::CompositeCommandCaller> > > > >._Freenode(_List_buy<std::list<FilterFramework::Ptr<Tree::CompositeCommandCaller>\,std::allocator<FilterFramework::Ptr<Tree::CompositeCommandCaller> > >\,std::allocator<std::list<FilterFramework::Ptr<Tree::CompositeCommandCaller>\,std::allocator<FilterFramework::Ptr<Tree::CompositeCommandCaller> > > > >* , _List_node<std::list<FilterFramework::Ptr<Tree::CompositeCommandCaller>\,std::allocator<FilterFramework::Ptr<Tree::CompositeCommandCaller> > >\,void \*>* _Pnode)
   at std.list<std::list<FilterFramework::Ptr<Tree::CompositeCommandCaller>,std::allocator<FilterFramework::Ptr<Tree::CompositeCommandCaller> > >,std::allocator<std::list<FilterFramework::Ptr<Tree::CompositeCommandCaller>,std::allocator<FilterFramework::Ptr<Tree::CompositeCommandCaller> > > > >.erase(list<std::list<FilterFramework::Ptr<Tree::CompositeCommandCaller>\,std::allocator<FilterFramework::Ptr<Tree::CompositeCommandCaller> > >\,std::allocator<std::list<FilterFramework::Ptr<Tree::CompositeCommandCaller>\,std::allocator<FilterFramework::Ptr<Tree::CompositeCommandCaller> > > > >* , _List_iterator<std::_List_val<std::_List_simple_types<std::list<FilterFramework::Ptr<Tree::CompositeCommandCaller>\,std::allocator<FilterFramework::Ptr<Tree::CompositeCommandCaller> > > > > >* , _List_const_iterator<std::_List_val<std::_List_simple_types<std::list<FilterFramework::Ptr<Tree::CompositeCommandCaller>\,std::allocator<FilterFramework::Ptr<Tree::CompositeCommandCaller> > > > > > _Where)
   at CollectiveCommander.EndCommonCompositeCommand()
   at FrameworkUndoBuffer.EndCommonCompositeOperation()
   at Sdl.TranslationStudio.Editor.TranslationEditor.Actions.SplitSegmentsAction.SplitSegment(IParagraphUnitContainerNode sourceParagraph, ISegmentContainerNode sourceSegment, IParagraphUnitContainerNode targetParagraph, ISegmentContainerNode targetSegment, SegmentId[]& newSegmentIds)
   at Sdl.TranslationStudio.Editor.TranslationEditor.Actions.SplitSegmentsAction.Execute()
   at Sdl.Desktop.Platform.Implementation.CommandBars.ActionService.<>c__DisplayClass30_0.<ExecuteAction>b__0()
   at Sdl.Desktop.Logger.Log.Resources(Object message, Action action)
   at Sdl.Desktop.Platform.Implementation.CommandBars.ActionService.ExecuteAction(IAction action, ActionOrigin origin, Boolean allowToggle)
   at Sdl.Desktop.Platform.WinForms.IgCommandBarAction.Execute()
   at Sdl.Desktop.Platform.WinForms.IgCommandBarAction._lazyButtonTool_ToolClick(Object sender, ToolClickEventArgs e)
   at Infragistics.Win.UltraWinToolbars.ToolBase.OnToolClick(ToolClickEventArgs e)
   at Infragistics.Win.UltraWinToolbars.UltraToolbarsManager.OnToolClick(ToolClickEventArgs e)
   at Infragistics.Win.UltraWinToolbars.UltraToolbarsManager.FireEvent(ToolbarEventIds id, EventArgs e)
   at Infragistics.Win.UltraWinToolbars.ToolBase.OnToolClick()
   at Infragistics.Win.UltraWinToolbars.ToolMenuItem.OnClick()
   at Infragistics.Win.UltraWinToolbars.PopupMenuItemUIElement.DoClickProcessing(MouseEventArgs e)
   at Infragistics.Win.UltraWinToolbars.PopupMenuItemUIElement.OnMouseUp(MouseEventArgs e)
   at Infragistics.Win.TextUIElementBase.OnMouseUp(MouseEventArgs e)
   at Infragistics.Win.ControlUIElementBase.ProcessMouseUpHelper(Object sender, MouseEventArgs e)
   at Infragistics.Win.ControlUIElementBase.ProcessMouseUp(Object sender, MouseEventArgs e)
   at Infragistics.Win.Utilities.ProcessEvent(Control control, ProcessEvent eventToProcess, EventArgs e)
   at Infragistics.Win.UltraWinToolbars.PopupControlBase.OnMouseUp(MouseEventArgs e)
   at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)]]></StackTrace>
  </Exception>
  <Environment>
    <ProductName>SDL Trados Studio</ProductName>
    <ProductVersion>15.0.0.0</ProductVersion>
    <EntryAssemblyFileVersion>15.2.5.2145</EntryAssemblyFileVersion>
    <OperatingSystem>Microsoft Windows 10 Enterprise</OperatingSystem>
    <ServicePack>NULL</ServicePack>
    <OperatingSystemLanguage>1033</OperatingSystemLanguage>
    <CodePage>1252</CodePage>
    <LoggedOnUser>danielhug</LoggedOnUser>
    <DotNetFrameWork>4.0.30319.42000</DotNetFrameWork>
    <ComputerName>ABCD</ComputerName>
    <ConnectedToNetwork>True</ConnectedToNetwork>
    <PhysicalMemory>12581868 MB</PhysicalMemory>
  </Environment>
</SDLErrorDetails>