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Power Platform Community / Forums / Power Automate / launch new firefox: fa...
Power Automate
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launch new firefox: failed to assume control, firefox fails to load

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Posted on by 10

Loaded up PAD.  Opened Firefox in a flow the first couple times, but now nothing happens, Firefox does not load, get the "Failed to assume control of firefox" error.  I have verified the extension , and rebooted the machine.  First command on the flow, and fails each time.

 

First day playing with it, doesn't bode well.

 

Thanx

 

Phil

  • kinuasa Profile Picture
    803 Most Valuable Professional on at
  • Agnius Bartninkas Profile Picture
    Most Valuable Professional on at

    We have noticed that the extension does not always load well on time for Chrome and thus PAD fails to assume control of it, even though the Chrome window gets opened. We don't really use Firefox in our flows, but perhaps a similar issue can cause it.

    I would normally suggest using the Run application action to run the browser with some URL, then Wait for window to wait for it to appear, then Launch new Firefox to attach to the existing instance, instead of launching a new one. This works without failure for Chrome at least.

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  • PhilSmith Profile Picture
    10 on at

    Went through the whole shebang, nothing hit a chord here from any of the three documents.

  • PhilSmith Profile Picture
    10 on at

    Nope.  Even if Firefox is already running, the lauch new firefox action does not open a new instance of firefox, or a new window, and I get the same error.

     

     

  • Verified answer
    Agnius Bartninkas Profile Picture
    Most Valuable Professional on at

    What I meant was that when you use Run application it already opens Firefox. Then you should use Launch new Firefox, but instead of making it launch a new instance, make it Attach to an existing instance (the one you launched via Run application). Make sure you add a Wait for window action in there to wait for Firefox to actually open and load the page, before you try to attach to it.

     

    Here's a snippet I commonly use when launching a browser:

    SET URL TO $'''{SomeURL}'''
    System.RunApplication.RunApplication ApplicationPath: $'''chrome''' CommandLineArguments: $'''www.google.com''' WorkingDirectory: '' WindowStyle: System.ProcessWindowStyle.Maximized ProcessId=> AppProcessId
    WAIT (UIAutomation.WaitForWindow.ToOpenByTitleClass Title: $'''Google*''' Class: $'''Chrome_WidgetWin_1''' FocusWindow: True) FOR 30
    WebAutomation.LaunchChrome.AttachToChromeByTitle TabTitle: $'''Google''' AttachTimeout: 5 BrowserInstance=> BrowserMain
    ON ERROR REPEAT 5 TIMES WAIT 3
    END
    WebAutomation.GoToWebPage.GoToWebPageCloseDialog BrowserInstance: BrowserMain Url: URL

     

    You can copy and paste this into your PAD designer to have the actions created for you.

    If you do, note the following things:

    1. This is designed to work with Google Chrome. If you want to use Firefox, you will need to modify those actions to:
      1. Run a different application
      2. Wait for a window with a different title
      3. Use a different Launch browser action
    2. You need to replace the {SomeURL} placeholder with an actual URL that you want to navigate to.

    This has worked for me without fail for several years now, when sometimes simply using Launch new Chrome fails due to the extension not loading properly.

    -------------------------------------------------------------------------
    If I have answered your question, please mark it as the preferred solution. If you like my response, please give it a Thumbs Up.

    I also provide paid consultancy and development services using Power Automate. If you're interested, DM me and we can discuss it.

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