I'm having problems when trying to save a terminus in the MultiTerm window, which I keep open in the Editor while translating. I use Studio 2019.

 and Windows 10. Here the error details:

<SDLErrorDetails time="13.08.2018 16:18:03">
  <ErrorMessage>
Unknown Error</ErrorMessage>
  <Exception>
    <Type>System.NullReferenceException, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</Type>
    <HelpLink />
    <Source>Entry</Source>
    <HResult>-2147467261</HResult>
    <StackTrace><![CDATA[   bei Sdl.MultiTerm.TMO.Interop.EntryClass.Save()
   bei Sdl.MultiTerm.Client.UI.Viewer.ScriptingHost.SaveEntry(String content)]]></StackTrace>
  </Exception>
  <Environment>
    <ProductName>SDL Trados Studio</ProductName>
    <ProductVersion>15.0.0.0</ProductVersion>
    <EntryAssemblyFileVersion>15.0.0.29074</EntryAssemblyFileVersion>
    <OperatingSystem>Microsoft Windows 10 Home</OperatingSystem>
    <ServicePack>NULL</ServicePack>
    <OperatingSystemLanguage>1031</OperatingSystemLanguage>
    <CodePage>1252</CodePage>
    <LoggedOnUser>FUTURAGS\Gio</LoggedOnUser>
    <DotNetFrameWork>4.0.30319.42000</DotNetFrameWork>
    <ComputerName>FUTURAGS</ComputerName>
    <ConnectedToNetwork>True</ConnectedToNetwork>
    <PhysicalMemory>8326368 MB</PhysicalMemory>
  </Environment>
</SDLErrorDetails>