Can't open Form Designer and Form Renderer does not load

Hello. I’m trying to open the Form Designer but I am encountering this error:
image

Additionally, the Form Renderer doesn’t seem to load at all. Does anyone know what’s causing these issues? What could be a possible solution for these?

Any help regarding this information would be helpful. Thank you!

Here is the stack trace just in case:

21.4.4+Branch.master.Sha.a8b5101efe02651274064093e9c7410fedff7696

There was no endpoint listening at net.pipe://localhost/UiPath.OutOfProcessUi.Host.WCF/BrokerService_IOutOfProcessUiService_7964 that could accept the message. This is often caused by an incorrect address or SOAP action. See InnerException, if present, for more details.

Error: System.Exception: There was no endpoint listening at net.pipe://localhost/UiPath.OutOfProcessUi.Host.WCF/BrokerService_IOutOfProcessUiService_7964 that could accept the message. This is often caused by an incorrect address or SOAP action. See InnerException, if present, for more details.

Server stack trace: 
   at System.ServiceModel.Channels.ConnectionUpgradeHelper.DecodeFramingFault(ClientFramingDecoder decoder, IConnection connection, Uri via, String contentType, TimeoutHelper& timeoutHelper)
   at System.ServiceModel.Channels.ClientFramingDuplexSessionChannel.SendPreamble(IConnection connection, ArraySegment`1 preamble, TimeoutHelper& timeoutHelper)
   at System.ServiceModel.Channels.ClientFramingDuplexSessionChannel.DuplexConnectionPoolHelper.AcceptPooledConnection(IConnection connection, TimeoutHelper& timeoutHelper)
   at System.ServiceModel.Channels.ConnectionPoolHelper.EstablishConnection(TimeSpan timeout)
   at System.ServiceModel.Channels.ClientFramingDuplexSessionChannel.OnOpen(TimeSpan timeout)
   at System.ServiceModel.Channels.CommunicationObject.Open(TimeSpan timeout)
   at System.ServiceModel.Channels.ServiceChannel.OnOpen(TimeSpan timeout)
   at System.ServiceModel.Channels.CommunicationObject.Open(TimeSpan timeout)
   at System.ServiceModel.Channels.ServiceChannel.CallOpenOnce.System.ServiceModel.Channels.ServiceChannel.ICallOnce.Call(ServiceChannel channel, TimeSpan timeout)
   at System.ServiceModel.Channels.ServiceChannel.CallOnceManager.CallOnce(TimeSpan timeout, CallOnceManager cascade)
   at System.ServiceModel.Channels.ServiceChannel.EnsureOpened(TimeSpan timeout)
   at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout)
   at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage methodCall, ProxyOperationRuntime operation)
   at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message)

Exception rethrown at [0]: 
   at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
   at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
   at UiPath.OutOfProcessUi.Common.Interface.IProcessControl.InitializeProcess(String[] nugetPaths, Int32 studioProcessId)
   at UiPath.OutOfProcessUi.Common.Client.OutOfProcessUiClient.InitializeProcess(String[] assemblyPaths)
   at UiPath.OutOfProcessUi.Common.Client.OutOfProcessUiClient.CreateInstance(Int32 timeout)
   at UiPath.OutOfProcessUi.Common.Client.OutOfProcessUiCreator.GetOutOfProcessUiStarter(Int32 timeout)
   at UiPath.Form.ActivityLibrary.FormLibrary.DesignForm(String formSchemaJson, FormDesignOptions formDesignOptions)
   at UiPath.Form.ActivityLibrary.FormLibrary.DesignForm(Dictionary`2 fieldsCollection, FormDesignOptions formDesignOptions, String existingFormSchemaJson)
   at UiPath.Form.Activities.Design.FormActivityDesigner.OpenFormDesigner(Object sender, RoutedEventArgs e)
   at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
   at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
   at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
   at System.Windows.UIElement.RaiseEvent(RoutedEventArgs e)
   at System.Windows.Controls.Primitives.ButtonBase.OnClick()
   at System.Windows.Controls.Button.OnClick()
   at System.Windows.Controls.Primitives.ButtonBase.OnMouseLeftButtonUp(MouseButtonEventArgs e)
   at System.Windows.UIElement.OnMouseLeftButtonUpThunk(Object sender, MouseButtonEventArgs e)
   at System.Windows.Input.MouseButtonEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget)
   at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
   at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
   at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
   at System.Windows.UIElement.ReRaiseEventAs(DependencyObject sender, RoutedEventArgs args, RoutedEvent newEvent)
   at System.Windows.UIElement.OnMouseUpThunk(Object sender, MouseButtonEventArgs e)
   at System.Windows.Input.MouseButtonEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget)
   at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
   at System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
   at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
   at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
   at System.Windows.UIElement.RaiseTrustedEvent(RoutedEventArgs args)
   at System.Windows.UIElement.RaiseEvent(RoutedEventArgs args, Boolean trusted)
   at System.Windows.Input.InputManager.ProcessStagingArea()
   at System.Windows.Input.InputManager.ProcessInput(InputEventArgs input)
   at System.Windows.Input.InputProviderSite.ReportInput(InputReport inputReport)
   at System.Windows.Interop.HwndMouseInputProvider.ReportInput(IntPtr hwnd, InputMode mode, Int32 timestamp, RawMouseActions actions, Int32 x, Int32 y, Int32 wheel)
   at System.Windows.Interop.HwndMouseInputProvider.FilterMessage(IntPtr hwnd, WindowMessage msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
   at System.Windows.Interop.HwndSource.InputFilterMessage(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), HResult -2146233087

@Raphael_Omila

Welcome to our UiPath community.

Can you please uninstall UiPath.Form.Activities package and then reinstall it again and check it once.