Automation of WoldServer Package Import not running after Migration to Studio 2021

Hi community

After having migrated some Studio 2019 automations to Studio 2021 without problems I am stuck with migrating an automation that imports Worldserver packages and saves SDL Projects. I know that Worldserver support has been moved into a separate plugin, and when I look into the program Folder I find diferent DLLs
2019: Sdl.TranslationStudio.Packaging.Convertors.WorldServer.dll
2021: Sdl.TranslationStudio.Packaging.WorldServer.dll   

This is the part of the code that throws the error:

If Not IO.File.Exists(WSXZ.Replace(".wsxz", ".sdlppx")) Then

Dim XX As New WsPackageConvertor

TraceLog("Prepare: " & WSXZ.Replace(".wsxz", ".sdlppx"))

XX.ConvertPackage(WSXZ, WSXZ.Replace(".wsxz", ".sdlppx"))

XX = Nothing

End If

 

Can you give me a hint on how to fix that?

 

Error message:

System.NullReferenceException: Der Objektverweis wurde nicht auf eine Objektinstanz festgelegt.

   bei Sdl.Desktop.Platform.Implementation.Services.MessageService.ShowErrorImplementation(IWin32Window owner, Exception ex, String message, Boolean useExceptionDisplayInfo, Boolean logException)

   bei Sdl.Desktop.Platform.Implementation.Services.MessageService.ShowError(Exception ex, String message)

   bei Sdl.Desktop.Platform.Implementation.Services.GlobalServiceContext.GetService[T]()

   bei Sdl.Desktop.Platform.Implementation.Services.GlobalServiceContext.TryGetService[T](T& service)

   bei Sdl.ProjectApi.Implementation.Factory.CreateApplication(ILanguageCloudService languageCloudService)

   bei Sdl.TranslationStudio.Packaging.Convertors.WorldServer.WsPackageConvertor.GetProjectsProvider()

   bei Sdl.TranslationStudio.Packaging.WorldServer.Ws2RivelinConverter.Convert(Boolean runAnalysisTask)

   bei Sdl.TranslationStudio.Packaging.Convertors.WorldServer.WsPackageConvertor.ConvertPackage(String wsPackageFilePath, String targetPackagePath, Boolean runAnalysisTask, ImportSettings tmImportSettings)

   bei Sdl.TranslationStudio.Packaging.Convertors.WorldServer.WsPackageConvertor.ConvertPackage(String wsPackageFilePath, String targetPackagePath)

   bei convertWSXZ.Form1.Form1_Load(Object sender, EventArgs e) in ...\Form1.vb:Zeile 193.