The committed RadSpreadsheetRibbon_style.xaml renders the AI group unconditionally:

<telerikRibbon:RadRibbonGroup Header="AI">

Workaround: 

private void HideAIButton()
{
    var aiButton = this.spreadsheetRibbon
        .ChildrenOfType<RadRibbonButton>()
        .FirstOrDefault(b => b.Text == "AI Tools");
    if (aiButton == null)
    {
        return;
    }

    var aiGroup = aiButton.ParentOfType<RadRibbonGroup>();
    if (aiGroup != null)
    {
        aiGroup.Visibility = Visibility.Collapsed;
    }
    else
    {
        aiButton.Visibility = Visibility.Collapsed;
    }
}

   private string? LoadDocx(
      string path)
   {
      string? msg = null;
      try
      {
         using var instream = File.OpenRead(path);

         var openXmlRadDocProvider =
            new Telerik.Windows.Documents.FormatProviders.OpenXml.Docx.DocxFormatProvider();

         var raddoc = openXmlRadDocProvider.Import(instream);
         RadRtb.Document = raddoc;
      }
      catch (Exception ex)
      {
         msg = ex.Message;
      }

      return msg;
   }

public MyWpfUserControl()
{
    TelerikLicensing.Register("your-script-key");
    InitializeComponent();
}

C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\Microsoft.WinFx.targets(268,9): error MC1000: Unknown build error, 'Cannot resolve dependency to assembly 'Telerik.Licensing.Runtime, Version=1.4.6.0, Culture=neutral, PublicKeyToken=keyhere' because it has not been preloaded. When using the ReflectionOnly APIs, dependent assemblies must be pre-loaded or loaded on demand through the ReflectionOnlyAssemblyResolve event.'

<ItemGroup>
	<PackageReference Include="Telerik.Licensing" Version="1.4.*" />
</ItemGroup>

Application: Rueckrufdatenbank.exe
CoreCLR Version: 9.0.124.61010
.NET Version: 9.0.1
Description: The process was terminated due to an unhandled exception.
Exception Info: Prism.Ioc.ContainerResolutionException: An unexpected error occurred while resolving 'Rueckrufdatenbank.Views.MainWindow'
 ---> Unity.ResolutionFailedException: Resolution failed with error: Exception has been thrown by the target of an invocation.

For more detailed information run Unity in debug mode: new UnityContainer().AddExtension(new Diagnostic())
 ---> System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation.
 ---> System.Windows.Markup.XamlParseException: Bei der Initialisierung von "Telerik.Windows.Controls.RadRibbonButton" wurde eine Ausnahme ausgelöst.
 ---> System.Xaml.XamlObjectWriterException: Beim Festlegen der Eigenschaft "System.Windows.ResourceDictionary.Source" wurde eine Ausnahme ausgelöst.
 ---> System.Windows.Markup.XamlParseException: Beim Festlegen der Eigenschaft "System.Windows.ResourceDictionary.DeferrableContent" wurde eine Ausnahme ausgelöst.
 ---> System.Xaml.XamlObjectWriterException: Fehler beim Erstellen von "ElementType" aus dem Text "Button".
 ---> System.IO.FileNotFoundException: Could not load file or assembly 'WindowsFormsIntegration, Culture=neutral, PublicKeyToken=31bf3856ad364e35'. Das System kann die angegebene Datei nicht finden.
File name: 'WindowsFormsIntegration, Culture=neutral, PublicKeyToken=31bf3856ad364e35'
   at System.Reflection.RuntimeAssembly.InternalLoad(AssemblyName assemblyName, StackCrawlMark& stackMark, AssemblyLoadContext assemblyLoadContext, RuntimeAssembly requestingAssembly, Boolean throwOnFileNotFound)
   at System.Reflection.Assembly.Load(AssemblyName assemblyRef)
   at System.Windows.Baml2006.Baml2006SchemaContext.ResolveAssembly(BamlAssembly bamlAssembly)
   at System.Windows.Baml2006.Baml2006SchemaContext.GetAssembly(Int16 assemblyId)
   at System.Windows.Baml2006.Baml2006SchemaContext.EnsureXmlnsAssembliesLoaded(String xamlNamespace)
   at System.Windows.Baml2006.Baml2006SchemaContext.GetXamlType(String xamlNamespace, String name, XamlType[] typeArguments)
   at MS.Internal.Xaml.XamlContext.GetXamlType(XamlTypeName typeName, Boolean returnUnknownTypesOnFailure, Boolean skipVisibilityCheck)
   at MS.Internal.Xaml.XamlContext.ResolveXamlType(String qName, Boolean skipVisibilityCheck)
   at MS.Internal.Xaml.Context.ObjectWriterContext.ServiceProvider_Resolve(String qName)
   at MS.Internal.Xaml.Runtime.ClrObjectRuntime.CreateObjectWithTypeConverter(ServiceProviderContext serviceContext, XamlValueConverter`1 ts, Object value)
   at System.Xaml.XamlObjectWriter.Logic_CreateFromValue(ObjectWriterContext ctx, XamlValueConverter`1 typeConverter, Object value, XamlMember property, String targetName, IAddLineInfo lineInfo)
   --- End of inner exception stack trace ---
   at System.Xaml.XamlObjectWriter.Logic_CreateFromValue(ObjectWriterContext ctx, XamlValueConverter`1 typeConverter, Object value, XamlMember property, String targetName, IAddLineInfo lineInfo)
   at System.Xaml.XamlObjectWriter.Logic_CreatePropertyValueFromValue(ObjectWriterContext ctx)
   at System.Xaml.XamlObjectWriter.WriteEndMember()
   at System.Xaml.XamlServices.Transform(XamlReader xamlReader, XamlWriter xamlWriter, Boolean closeWriter)
   at System.Windows.ResourceDictionary.EvaluateMarkupExtensionNodeList(XamlReader reader, IServiceProvider serviceProvider)
   at System.Windows.ResourceDictionary.SetKeys(IList`1 keyCollection, IServiceProvider serviceProvider)
   at MS.Internal.Xaml.Runtime.ClrObjectRuntime.SetValue(Object inst, XamlMember property, Object value)
   --- End of inner exception stack trace ---
   at System.Windows.Markup.XamlReader.RewrapException(Exception e, IXamlLineInfo lineInfo, Uri baseUri)
   at System.Windows.Markup.WpfXamlLoader.Load(XamlReader xamlReader, IXamlObjectWriterFactory writerFactory, Boolean skipJournaledProperties, Object rootObject, XamlObjectWriterSettings settings, Uri baseUri)
   at System.Windows.Markup.WpfXamlLoader.LoadBaml(XamlReader xamlReader, Boolean skipJournaledProperties, Object rootObject, XamlAccessLevel accessLevel, Uri baseUri)
   at System.Windows.Markup.XamlReader.LoadBaml(Stream stream, ParserContext parserContext, Object parent, Boolean closeStream)
   at System.Windows.Application.LoadBamlStreamWithSyncInfo(Stream stream, ParserContext pc)
   at MS.Internal.AppModel.AppModelKnownContentFactory.BamlConverterCore(Stream stream, Uri baseUri, Boolean canUseTopLevelBrowser, Boolean sandboxExternalContent, Boolean allowAsync, Boolean isJournalNavigation, XamlReader& asyncObjectConverter, Boolean isUnsafe)
   at MS.Internal.AppModel.MimeObjectFactory.GetObjectAndCloseStreamCore(Stream s, ContentType contentType, Uri baseUri, Boolean canUseTopLevelBrowser, Boolean sandboxExternalContent, Boolean allowAsync, Boolean isJournalNavigation, XamlReader& asyncObjectConverter, Boolean isUnsafe)
   at System.Windows.ResourceDictionary.set_Source(Uri value)
   at MS.Internal.Xaml.Runtime.ClrObjectRuntime.SetValue(Object inst, XamlMember property, Object value)
   --- End of inner exception stack trace ---
   at MS.Internal.Xaml.Runtime.ClrObjectRuntime.SetValue(Object inst, XamlMember property, Object value)
   at MS.Internal.Xaml.Runtime.PartialTrustTolerantRuntime.SetValue(Object obj, XamlMember property, Object value)
   at System.Xaml.XamlObjectWriter.Logic_ApplyPropertyValue(ObjectWriterContext ctx, XamlMember prop, Object value, Boolean onParent)
   at System.Xaml.XamlObjectWriter.Logic_DoAssignmentToParentProperty(ObjectWriterContext ctx)
   at System.Xaml.XamlObjectWriter.WriteEndMember()
   at System.Xaml.XamlServices.Transform(XamlReader xamlReader, XamlWriter xamlWriter, Boolean closeWriter)
   at System.Windows.SystemResources.ResourceDictionaries.LoadDictionary(Assembly assembly, String assemblyName, String resourceName, Boolean isTraceEnabled, Uri& dictionarySourceUri)
   at System.Windows.SystemResources.ResourceDictionaries.LoadGenericDictionary(Boolean isTraceEnabled)
   at System.Windows.SystemResources.FindDictionaryResource(Object key, Type typeKey, ResourceKey resourceKey, Boolean isTraceEnabled, Boolean allowDeferredResourceReference, Boolean mustReturnDeferredResourceReference, Boolean& canCache)
   at System.Windows.SystemResources.FindResourceInternal(Object key, Boolean allowDeferredResourceReference, Boolean mustReturnDeferredResourceReference)
   at System.Windows.StyleHelper.GetThemeStyle(FrameworkElement fe, FrameworkContentElement fce)
   at System.Windows.FrameworkElement.UpdateThemeStyleProperty()
   at System.Windows.FrameworkElement.OnPropertyChanged(DependencyPropertyChangedEventArgs e)
   at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args)
   at System.Windows.DependencyObject.UpdateEffectiveValue(EntryIndex entryIndex, DependencyProperty dp, PropertyMetadata metadata, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType)
   at System.Windows.DependencyObject.SetValueCommon(DependencyProperty dp, Object value, PropertyMetadata metadata, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType, Boolean isInternal)
   at System.Windows.DependencyObject.SetValue(DependencyProperty dp, Object value)
   at Telerik.Windows.Controls.Theme.DefaultStyleKeyHelper.SetDefaultStyleKey(Control control, Object value)
   at Telerik.Windows.Controls.StyleManager.SetDefaultStyleKey(Control control, Type controlType)
   at Telerik.Windows.Controls.RadButton.OnInitialized(EventArgs e)
   at Telerik.Windows.Controls.RadRibbonButton.OnInitialized(EventArgs e)
   at MS.Internal.Xaml.Runtime.ClrObjectRuntime.InitializationGuard(XamlType xamlType, Object obj, Boolean begin)
   --- End of inner exception stack trace ---
   at System.Windows.Markup.XamlReader.RewrapException(Exception e, IXamlLineInfo lineInfo, Uri baseUri)
   at System.Windows.Markup.WpfXamlLoader.Load(XamlReader xamlReader, IXamlObjectWriterFactory writerFactory, Boolean skipJournaledProperties, Object rootObject, XamlObjectWriterSettings settings, Uri baseUri)
   at System.Windows.Markup.WpfXamlLoader.LoadBaml(XamlReader xamlReader, Boolean skipJournaledProperties, Object rootObject, XamlAccessLevel accessLevel, Uri baseUri)
   at System.Windows.Markup.XamlReader.LoadBaml(Stream stream, ParserContext parserContext, Object parent, Boolean closeStream)
   at System.Windows.Application.LoadComponent(Object component, Uri resourceLocator)
   at Rueckrufdatenbank.Views.MainWindow.InitializeComponent() in C:\GitLocal\Rueckrufdatenbank\Rueckrufdatenbank\Views\MainWindow.xaml:line 1
   at Rueckrufdatenbank.Views.MainWindow..ctor() in C:\GitLocal\Rueckrufdatenbank\Rueckrufdatenbank\Views\MainWindow.xaml.cs:line 13
   at System.RuntimeMethodHandle.InvokeMethod(Object target, Void** arguments, Signature sig, Boolean isConstructor)
   at System.Reflection.MethodBaseInvoker.InvokeWithNoArgs(Object obj, BindingFlags invokeAttr)
   --- End of inner exception stack trace ---
   at System.Reflection.MethodBaseInvoker.InvokeWithNoArgs(Object obj, BindingFlags invokeAttr)
   at System.Reflection.RuntimeConstructorInfo.Invoke(BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at System.Reflection.ConstructorInfo.Invoke(Object[] parameters)
   at Unity.Processors.ConstructorProcessor.<>c__DisplayClass16_0.<GetResolverDelegate>b__0(BuilderContext& c)
   at Unity.Processors.MemberProcessor`2.<>c__DisplayClass8_0.<GetResolver>b__0(BuilderContext& c)
   at Unity.Processors.MemberProcessor`2.<>c__DisplayClass8_0.<GetResolver>b__0(BuilderContext& c)
   at Unity.Processors.MemberProcessor`2.<>c__DisplayClass8_0.<GetResolver>b__0(BuilderContext& c)
   at Unity.UnityContainer.<>c__DisplayClass113_0.<OptimizingFactory>b__0(BuilderContext& c)
   at Unity.Strategies.BuildPlanStrategy.PreBuildUp(BuilderContext& context)
   at Unity.UnityContainer.<>c.<.ctor>b__73_1(BuilderContext& context)
   --- End of inner exception stack trace ---
   at Unity.UnityContainer.<>c.<.ctor>b__73_1(BuilderContext& context)
   at Unity.UnityContainer.Unity.IUnityContainer.Resolve(Type type, String name, ResolverOverride[] overrides)
   at Prism.Unity.UnityContainerExtension.Resolve(Type type, ValueTuple`2[] parameters)
   --- End of inner exception stack trace ---
   at Prism.Unity.UnityContainerExtension.Resolve(Type type, ValueTuple`2[] parameters)
   at Prism.Unity.UnityContainerExtension.Resolve(Type type)
   at Prism.Ioc.IContainerProviderExtensions.Resolve[T](IContainerProvider provider)
   at Rueckrufdatenbank.App.CreateShell() in C:\GitLocal\Rueckrufdatenbank\Rueckrufdatenbank\App.xaml.cs:line 67
   at Prism.PrismApplicationBase.Initialize()
   at Prism.PrismApplicationBase.InitializeInternal()
   at Prism.PrismApplicationBase.OnStartup(StartupEventArgs e)
   at Rueckrufdatenbank.App.OnStartup(StartupEventArgs e) in C:\GitLocal\Rueckrufdatenbank\Rueckrufdatenbank\App.xaml.cs:line 75
   at System.Windows.Application.<.ctor>b__1_0(Object unused)
   at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
   at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)
   at System.Windows.Threading.DispatcherOperation.InvokeImpl()
   at MS.Internal.CulturePreservingExecutionContext.CallbackWrapper(Object obj)
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
--- End of stack trace from previous location ---
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
   at MS.Internal.CulturePreservingExecutionContext.Run(CulturePreservingExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Windows.Threading.DispatcherOperation.Invoke()
   at System.Windows.Threading.Dispatcher.ProcessQueue()
   at System.Windows.Threading.Dispatcher.WndProcHook(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
   at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
   at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
   at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
   at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)
   at System.Windows.Threading.Dispatcher.LegacyInvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs)
   at System.Windows.Threading.Dispatcher.Invoke(DispatcherPriority priority, Delegate method, Object arg)
   at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)
   at MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg)
   at System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame)
   at System.Windows.Application.RunDispatcher(Object ignore)
   at System.Windows.Application.RunInternal(Window window)
   at Rueckrufdatenbank.App.Main()

CSC : error CS0006: Metadata file 'dll/file/path/here.dll' could not be found [project directory path here]