Unexpected exception when initializing view part Fragment Matches

<SDLErrorDetails time="17-2-2020 11:22:56">
  <ErrorMessage>Cannot access site for type Sdl.TranslationStudio.Editor.Previews.InternalPreview.InternalPreviewViewPart before the view part has been initialized.</ErrorMessage>
  <Exception>
    <Type>System.InvalidOperationException, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</Type>
    <HelpLink />
    <Source>Sdl.Desktop.Platform</Source>
    <HResult>-2146233079</HResult>
    <StackTrace><![CDATA[   bij Sdl.Desktop.Platform.AbstractViewPart.get_ViewPartSite()
   bij Sdl.Desktop.Platform.AbstractViewWithParts.ShouldShowViewPartCommandBarProvider(IViewPartCommandBarProvider p)
   bij Sdl.Desktop.Platform.AbstractViewWithParts.UpdateViewPartCommandBarProviderVisibility()
   bij Sdl.Desktop.Platform.AbstractViewWithParts.RegisterViewPartCommandBarProvider(IViewPartCommandBarProvider viewPartCommandBarProvider)
   bij Sdl.TranslationStudio.Editor.Shared.DocumentViewProviderReference.get_DocumentViewProvider()
   bij Sdl.TranslationStudio.Api.Editor.AbstractInternalDocument..ctor(AbstractInternalEditor editor, IDocumentDescriptor descriptor)
   bij Sdl.TranslationStudio.Editor.TranslationEditor.TranslatableDocument..ctor(TranslatableDocumentEditor editor, ITranslatableDocumentDescriptor descriptor, ITranslatableDocumentEditorConfiguration configuration)
   bij Sdl.TranslationStudio.Editor.TranslationEditor.TranslatableDocumentEditor.CreateDocument(IDocumentDescriptor descriptor)
   bij Sdl.TranslationStudio.Api.Editor.AbstractInternalEditor.OpenDocument(IDocumentDescriptor descriptor, IInternalEditorContext context)
   bij Sdl.TranslationStudio.Editor.EditorService.CreateDocument(IAbstractEditor editor, IDocumentDescriptor descriptor, IEditorConfiguration configuration)
   bij Sdl.TranslationStudio.Editor.EditorService.OpenImpl(IDocumentDescriptor[] descriptors, IAbstractEditor[] editors, IEditorConfiguration[] configurations)
   bij Sdl.TranslationStudio.Editor.EditorService.OpenTranslatableFiles(ITranslatableFile[] translatableFiles, WorkflowStage[] stages)
   bij Sdl.TranslationStudio.Common.Files.FileUtil.OpenTranslatableFiles(IEditorService service, ITranslatableFile[] files, Nullable`1 workflowStage)
   bij Sdl.TranslationStudio.Common.Files.FileListControl.List_DefaultAction(Object sender, EventArgs e)
   bij Sdl.Desktop.Common.DataList.OnDefaultAction(EventArgs e)
   bij Sdl.Desktop.Common.DataList.BodyControl.OnDoubleClick(EventArgs e)
   bij System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks)
   bij System.Windows.Forms.Control.WndProc(Message& m)
   bij System.Windows.Forms.ScrollableControl.WndProc(Message& m)
   bij System.Windows.Forms.ContainerControl.WndProc(Message& m)
   bij System.Windows.Forms.UserControl.WndProc(Message& m)
   bij System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   bij System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   bij 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>15.1.0.44109</EntryAssemblyFileVersion>
    <OperatingSystem>Microsoft Windows 10 Home</OperatingSystem>
    <ServicePack>NULL</ServicePack>
    <OperatingSystemLanguage>1043</OperatingSystemLanguage>
    <CodePage>1252</CodePage>
    <LoggedOnUser>DESKTOP-P4LF2TG\vibek</LoggedOnUser>
    <DotNetFrameWork>4.0.30319.42000</DotNetFrameWork>
    <ComputerName>DESKTOP-P4LF2TG</ComputerName>
    <ConnectedToNetwork>True</ConnectedToNetwork>
    <PhysicalMemory>16704884 MB</PhysicalMemory>
  </Environment>
</SDLErrorDetails>