Error message "An item with the same key has already been added" keep poping up an it prevents me to keep typing

<SDLErrorDetails time="2017/07/28 10:34:16">
  <ErrorMessage>同一のキーを含む項目が既に追加されています。</ErrorMessage>
  <Exception>
    <Type>System.ArgumentException, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</Type>
    <ParamName />
    <HelpLink />
    <Source>mscorlib</Source>
    <HResult>-2147024809</HResult>
    <StackTrace><![CDATA[   場所 System.ThrowHelper.ThrowArgumentException(ExceptionResource resource)
   場所 System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add)
   場所 System.Collections.Generic.Dictionary`2.Add(TKey key, TValue value)
   場所 Sdl.MultiTerm.Core.XmlProcessor.EntryXmlProcessor.Transform(String inputXml)
   場所 Sdl.MultiTerm.Client.TerminologyProvider.TerminologyPrioviders.AbstractMultiTermTerminologyProvider.GetEntry(MultiTermTermbase termbase, Int32 id)
   場所 Sdl.MultiTerm.Client.TerminologyProvider.MultiTermTermbase.GetEntry(Int32 id)
   場所 Sdl.MultiTerm.Client.TerminologyProvider.TerminologyPrioviders.AbstractMultiTermTerminologyProvider.GetEntry(Int32 id)
   場所 Sdl.MultiTerm.Client.TerminologySearch.TermRecognitionHit.get_Entry()
   場所 Sdl.TranslationStudio.Editor.Terminology.TermBaseAutoSuggestProvider.GetSuggestionData(EditingContext context)
   場所 Sdl.TranslationStudio.Editor.TranslationEditor.Intellisense.SuggestionDataProviders.GetSuggestionData(EditingContext context)
   場所 Sdl.TranslationStudio.Editor.TranslationEditor.Intellisense.SuggestionWindow.ShowSuggestionWindow(Form parent, ISideBySideDocumentEditingView view, SideBySideEditor editor, ISuggestionDataProvider suggestionDataProvider, SuggestionSite site, Char firstChar, Int32 sourceStartPosition, SuggestionMode mode, ITranslatableDocumentEditorSettings settings, Boolean requireCaseResolving, Boolean incrementTextOffset, Int32 imeBehavior)
   場所 Sdl.TranslationStudio.Editor.TranslationEditor.Intellisense.IntellisenseEditing.ShowSuggestionWindow(Form parent, ISideBySideDocumentEditingView view, SideBySideEditor editor, ISuggestionDataProvider suggestionDataProvider, SuggestionSite site, Char firstChar, Int32 sourceStartPosition, SuggestionMode mode, ITranslatableDocumentEditorSettings settings, Boolean requireCaseResolving, Boolean incrementTextOffset)
   場所 Sdl.TranslationStudio.Editor.TranslationEditor.Intellisense.IntellisenseEditing.LaunchIntellisenseWindow(Boolean keyPressed, Char lastChar, Boolean afterImeCompositionUpdate)
   場所 Sdl.TranslationStudio.Editor.TranslationEditor.Intellisense.IntellisenseEditing.ProcessDocumentContentChanged(List`1 operations, Boolean afterImeCompositionUpdate)
   場所 Sdl.TranslationStudio.Editor.TranslationEditor.Intellisense.IntellisenseEditing.Editor_IMEEndComposition(Object sender, EventArgs e)
   場所 AbstractFrameworkEditControl.raise_IMEEndComposition(Object value0, EventArgs value1)
   場所 AbstractFrameworkEditControl.OnIMEEndComposition(Object sender, EventArgs args)
   場所 FrameworkEditControlEventSource.IMEEndComposition(FrameworkEditControlEventSource* )
   場所 Tree.DocumentControl.vl_WindowProc(DocumentControl* , HWND__* , UInt32 , UInt32 , Int32 )
   場所 FrameworkDocumentControl.vl_WindowProc(FrameworkDocumentControl* , HWND__* h_wnd, UInt32 n_msg, UInt32 w_p, Int32 l_p)
   場所 System.Windows.Forms.UnsafeNativeMethods.CallWindowProc(IntPtr wndProc, IntPtr hWnd, Int32 msg, IntPtr wParam, IntPtr lParam)
   場所 System.Windows.Forms.NativeWindow.DefWndProc(Message& m)
   場所 System.Windows.Forms.Control.DefWndProc(Message& m)
   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>
  </Exception>
  <Environment>
    <ProductName>SDL Trados Studio</ProductName>
    <ProductVersion>14.0.0.0</ProductVersion>
    <EntryAssemblyFileVersion>14.0.5889.5</EntryAssemblyFileVersion>
    <OperatingSystem>Microsoft Windows 10 Home</OperatingSystem>
    <ServicePack>NULL</ServicePack>
    <OperatingSystemLanguage>1041</OperatingSystemLanguage>
    <CodePage>932</CodePage>
    <LoggedOnUser>DESKTOP-KUMC9QA\tkaru</LoggedOnUser>
    <DotNetFrameWork>4.0.30319.42000</DotNetFrameWork>
    <ComputerName>DESKTOP-KUMC9QA</ComputerName>
    <ConnectedToNetwork>True</ConnectedToNetwork>
    <PhysicalMemory>8285272 MB</PhysicalMemory>
  </Environment>
</SDLErrorDetails>

Everytime I press "enter", "同一のキーを含む項目が既に追加されています。" (which means "An item with the same key has already been added") appears. Also, I can not delete what I typed in the target language column when I want to edit sentences. Trados 2017 was working fine until I changed the termbase setting, but now same error massage appears even I change the setting back to the way it was. Could you let me know what I can do to make Trados working properly again? Thank you.