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Power Platform Community / Forums / Power Automate / Problem starting up PA...
Power Automate
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Problem starting up PAD, Error with System NullReferenceException

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Posted on by JP1983 9

Just finished installed PAD in Amazon Workspace, after clicking add New flow

got following error log:

 

>>>>>>>>>>>>>>>>>

Message = Object reference not set to an instance of an object.
Error = System.NullReferenceException
Full text = System.NullReferenceException: Object reference not set to an instance of an object.
at System.Windows.Automation.Peers.AutomationPeer.EnsureChildren()
at System.Windows.Automation.Peers.AutomationPeer.UpdateChildrenInternal(Int32 invalidateLimit)
at System.Windows.Automation.Peers.ItemsControlAutomationPeer.UpdateChildren()
at System.Windows.Automation.Peers.AutomationPeer.UpdateSubtree()
at System.Windows.Automation.Peers.AutomationPeer.UpdateSubtree()
at System.Windows.Automation.Peers.AutomationPeer.UpdateSubtree()
at System.Windows.ContextLayoutManager.fireAutomationEvents()
at System.Windows.ContextLayoutManager.UpdateLayout()
at System.Windows.ContextLayoutManager.UpdateLayoutCallback(Object arg)
at System.Windows.Media.MediaContext.FireInvokeOnRenderCallbacks()
at System.Windows.Media.MediaContext.RenderMessageHandlerCore(Object resizedCompositionTarget)
at System.Windows.Media.MediaContext.RenderMessageHandler(Object resizedCompositionTarget)
at System.Windows.Interop.HwndTarget.OnResize()
at System.Windows.Interop.HwndTarget.HandleMessage(WindowMessage msg, IntPtr wparam, IntPtr lparam)
at System.Windows.Interop.HwndSource.HwndTargetFilterMessage(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)

>>>>>>>>>>>>>>>>>

 

Tried to find solutions, but no luck with that, anyone got any solutions or thoughts for this problem? Newbie with the Power Automate Desktop

Categories:
Power Automate Desktop
  • Agnius Bartninkas Profile Picture
    Agnius Bartninkas Most Valuable Professional on at

    Have you tried restarting the machine or reinstalling PAD?

  • JP1983 Profile Picture
    JP1983 9 on at

    Thanks for the suggestion, something changed. Thumbs UP~~😎
    After restarting AWS.
    Different log pops up before I entered PAD. Here is the message

    <

    An error occurred during cache initialization. Close Power Automate, navigate to D:\Users\tsqa04\AppData\Local\Microsoft\Power Automate Desktop path, make sure you have write access and try again.

    > I'll try to google it to see if I can find any thing.

     

     

    After I entered PAD, and after clicking Add new flow, slightly different log pop up.

    <

    Message = Object reference not set to an instance of an object.
    Error = System.NullReferenceException
    Full text = System.NullReferenceException: Object reference not set to an instance of an object.
    at System.Windows.Automation.Peers.AutomationPeer.EnsureChildren()
    at System.Windows.Automation.Peers.AutomationPeer.UpdateChildrenInternal(Int32 invalidateLimit)
    at System.Windows.Automation.Peers.ItemsControlAutomationPeer.UpdateChildren()
    at System.Windows.Automation.Peers.AutomationPeer.UpdateSubtree()
    at System.Windows.Automation.Peers.AutomationPeer.UpdateSubtree()
    at System.Windows.Automation.Peers.AutomationPeer.UpdateSubtree()
    at System.Windows.ContextLayoutManager.fireAutomationEvents()
    at System.Windows.ContextLayoutManager.UpdateLayout()
    at System.Windows.Controls.VirtualizingStackPanel.<>c__DisplayClass94_0.<InitializeViewport>b__0()
    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)

    >

  • JP1983 Profile Picture
    JP1983 9 on at

    I tried reinstalling and the same problem still pops up. 

    <

    Message = Object reference not set to an instance of an object.
    Error = System.NullReferenceException
    Full text = System.NullReferenceException: Object reference not set to an instance of an object.
    at System.Windows.Automation.Peers.AutomationPeer.EnsureChildren()
    at System.Windows.Automation.Peers.AutomationPeer.UpdateChildrenInternal(Int32 invalidateLimit)
    at System.Windows.Automation.Peers.ItemsControlAutomationPeer.UpdateChildren()
    at System.Windows.Automation.Peers.AutomationPeer.UpdateSubtree()
    at System.Windows.Automation.Peers.AutomationPeer.UpdateSubtree()
    at System.Windows.Automation.Peers.AutomationPeer.UpdateSubtree()
    at System.Windows.ContextLayoutManager.fireAutomationEvents()
    at System.Windows.ContextLayoutManager.UpdateLayout()
    at System.Windows.Controls.VirtualizingStackPanel.<>c__DisplayClass94_0.<InitializeViewport>b__0()
    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)

    >

     

    anyone have ideas to put into? thanks~!

  • MatheusWFranca Profile Picture
    MatheusWFranca 5 on at

    Same here, any solution?

  • JeffreyDSmith Profile Picture
    JeffreyDSmith 69 on at

    This happens quite often for me. I have narrowed down my problem to PAD forgetting my flows or a PAD editor defect for updating Runflow statements that call flows with passed variables or received variables with the called flows. The editor forgets to include the specifications for the passed or received variables on the Runflow statement. About a year ago, the PAD editor would prompt for the variables. Now PAD editor ignores the passed or received variables. I reported these problems a few times over the months, but Microsoft ignores the problems.

     

    Fortunately, I always save my flows as *.txt files with each flow name as the file name. I can re-install the flow with a few copy & paste actions, sometimes adding the specifications for the passed or received  variables. It is tedious and time-consuming, but there is nothing else that I can do.

  • RookAils1 Profile Picture
    RookAils1 136 on at

    Hi, just want to know, are you saying that you can edit your flow after re-installing pad ? and I cant even seem to create a new flow due to this error. " re-install the flow" means that you only deleted the flow and create a new one ?

  • JeffreyDSmith Profile Picture
    JeffreyDSmith 69 on at

    I can't see the flow, because PAD "forgets" it. I have to re-install the flow from my "copy & paste" backup. That's when things go downhill. Later, I start seeing duplicate flow names and NullReference crashes.

  • KrisStudio Profile Picture
    KrisStudio 5 on at

    I tried reinstalling V.2.41 PAD and deleting the folder AppData.
    can't solve.


    KrisStudio_0-1709275640246.png

     

  • CU16071609-1 Profile Picture
    CU16071609-1 6,255 Moderator on at

    @KrisStudio 

     

    Could you please downgrade your version to version 2.39 and see if it resolves your issue please?

     

  • RookAils1 Profile Picture
    RookAils1 136 on at

    Refer this thread, it works for me. check the last reply, there's a link for V2.39:

    https://powerusers.microsoft.com/t5/Power-Automate-Desktop/Erro-System-NullReferenceException/m-p/25...

     

    If in case someone still encountered this.

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