Failed to deactivate view 'Editor'

Hi,

Using Studio 2019 and got this message.

Current status:
- I cannot open the editor.
- I cannot close the editor.
- I cannot close the Studio.

Before this happened:
- I have completed a project and left the Studio open for a couple of hours.
- When I came back to my computer, the editor screen became blank and froze.

Attaching the file.

Thank you very for your support!

<SDLErrorDetails time="2020/12/23 21:01:10">
  <ErrorMessage>Failed to deactivate view 'エディタ'.</ErrorMessage>
  <Exception>
    <Type>Sdl.Desktop.Platform.StudioException, Sdl.Desktop.Platform, Version=15.2.0.0, Culture=neutral, PublicKeyToken=c28cdb26c445c888</Type>
    <HelpLink />
    <Source>Sdl.Desktop.Platform</Source>
    <HResult>-2146233088</HResult>
    <StackTrace><![CDATA[   場所 Sdl.Desktop.Platform.Implementation.StudioWindow.set_ActiveView(IViewReference value)
   場所 Sdl.Desktop.Platform.WinForms.StudioWindowForm._explorerBar_ActiveGroupChanged(Object sender, GroupEventArgs e)
   場所 Infragistics.Win.UltraWinExplorerBar.UltraExplorerBar.OnActiveGroupChanged(GroupEventArgs e)
   場所 Infragistics.Win.UltraWinExplorerBar.UltraExplorerBar.FireEvent(UltraExplorerBarEventIds id, EventArgs e)
   場所 Infragistics.Win.UltraWinExplorerBar.UltraExplorerBar.set_ActiveGroup(UltraExplorerBarGroup value)
   場所 Infragistics.Win.UltraWinExplorerBar.UltraExplorerBarGroupHeaderUIElement.OnMouseDown(MouseEventArgs e, Boolean adjustableArea, UIElement& captureMouseForElement)
   場所 Infragistics.Win.UIElement.OnMouseDown(MouseEventArgs e, Boolean adjustableArea, UIElement& captureMouseForElement)
   場所 Infragistics.Win.TextUIElementBase.OnMouseDown(MouseEventArgs e, Boolean adjustableArea, UIElement& captureMouseForElement)
   場所 Infragistics.Win.ControlUIElementBase.ProcessMouseDownHelper(Object sender, MouseEventArgs e)
   場所 Infragistics.Win.ControlUIElementBase.ProcessMouseDown(Object sender, MouseEventArgs e)
   場所 Infragistics.Win.Utilities.ProcessEvent(Control control, ProcessEvent eventToProcess, EventArgs e)
   場所 Infragistics.Win.UltraWinExplorerBar.UltraExplorerBar.OnMouseDown(MouseEventArgs e)
   場所 System.Windows.Forms.Control.WmMouseDown(Message& m, MouseButtons button, Int32 clicks)
   場所 System.Windows.Forms.Control.WndProc(Message& m)
   場所 System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   場所 System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   場所 System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)]]></StackTrace>
    <InnerException>
      <Type>System.NullReferenceException, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</Type>
      <HelpLink />
      <Source>Sdl.TranslationStudio.Editor</Source>
      <HResult>-2147467261</HResult>
      <StackTrace><![CDATA[   場所 Sdl.TranslationStudio.Editor.TranslationEditor.SideBySideDocumentEditingView.RemoveRetargetableActionHandlers()
   場所 Sdl.TranslationStudio.Editor.TranslationEditor.SideBySideDocumentEditingView.OnDeactivate()
   場所 Sdl.TranslationStudio.Api.Editor.AbstractInternalDocument.OnDeactivate()
   場所 Sdl.TranslationStudio.Editor.TranslationEditor.TranslatableDocument.OnDeactivate()
   場所 Sdl.TranslationStudio.Editor.EditorView.OnViewPartDeactivated(IViewPartReference viewPartReference)
   場所 Sdl.Desktop.Platform.AbstractViewWithParts.OnDeactivate()
   場所 Sdl.TranslationStudio.Editor.EditorView.OnDeactivate()
   場所 Sdl.Desktop.Platform.Implementation.ViewSite.OnDeactivate()
   場所 Sdl.Desktop.Platform.Implementation.StudioWindow.set_ActiveView(IViewReference value)]]></StackTrace>
    </InnerException>
  </Exception>
  <Environment>
    <ProductName>SDL Trados Studio</ProductName>
    <ProductVersion>15.0.0.0</ProductVersion>
    <EntryAssemblyFileVersion>15.2.0.1041</EntryAssemblyFileVersion>
    <OperatingSystem>Microsoft Windows 10 Home</OperatingSystem>
    <ServicePack>NULL</ServicePack>
    <OperatingSystemLanguage>1041</OperatingSystemLanguage>
    <CodePage>932</CodePage>
    <LoggedOnUser>LAPTOP-UDQE1LEG\naokoorito</LoggedOnUser>
    <DotNetFrameWork>4.0.30319.42000</DotNetFrameWork>
    <ComputerName>LAPTOP-UDQE1LEG</ComputerName>
    <ConnectedToNetwork>True</ConnectedToNetwork>
    <PhysicalMemory>4084100 MB</PhysicalMemory>
  </Environment>
</SDLErrorDetails>