Hello,
Since a couple of weeks, I get systematically the error in the title of this topic. The flow works perfectly. I haven't changed the code, so it wasn't suppose to dysfunction. I suspect an extra PAD problem. I tried various solutions :
- Reinstall the Microsoft Power Automate extension and try again. Same error.
- Try to install the extension to edge and chrome (with private navigation too). Same error.
- Control if "ComSpec" system variable exists, and it's the case.
- Reinstall PAD. Same problem.
Here are the screens for more information :


logs :
Microsoft.Flow.RPA.Desktop.Modules.SDK.ActionException: Impossible d’assurer le contrôle de Firefox (la communication avec le navigateur a échoué. Essayer de recharger l’extension). ---> Microsoft.Flow.RPA.Desktop.UIAutomation.WebAutomation.Core.Browser.WebBrowserException: Une exception de type 'Microsoft.Flow.RPA.Desktop.UIAutomation.WebAutomation.Core.Browser.WebBrowserException' a été levée.
à Microsoft.Flow.RPA.Desktop.UIAutomation.WebAutomation.Core.WebExtensionsBrowser.WebExtensionsBrowserLauncher.LaunchNew(ProcessWindowStyle processWindowStyle, String initialUrl, Int32 timeout, WebPageCourseOfActionIfDialogAppearsEnum dialogHandlingMode, String dialogButtonName)
à Microsoft.Flow.RPA.Desktop.UIAutomation.Plugin.Firefox.Firefox.StartNew(ProcessWindowStyle processWindowStyle, String initialUrl, Int32 timeout, WebPageCourseOfActionIfDialogAppearsEnum dialogHandlingMode, String dialogButtonName)
à Microsoft.Flow.RPA.Desktop.Modules.WebAutomation.Actions.WebAutomationActions.LaunchNewFirefox(String initialUrl, String firefoxTabTitle, String firefoxTabUrl, String dialogButtonToPress, Int32 operation, Int32 windowState, Int32 attachMode, Boolean waitForWebPageToLoad, Int32 waitForPageToLoadTimeout, Int32 courseOfActionIfDialogAppears, Boolean clearCache, Boolean clearCookies, Int32 timeout)
à Microsoft.Flow.RPA.Desktop.Modules.WebAutomation.Actions.LaunchFirefoxBase.Execute(ActionContext context)
--- Fin de la trace de la pile d'exception interne ---
à Microsoft.Flow.RPA.Desktop.Modules.WebAutomation.Actions.LaunchFirefoxBase.Execute(ActionContext context)
à Microsoft.Flow.RPA.Desktop.Robin.Engine.Execution.ActionRunner.Run(IActionStatement statement, Dictionary`2 inputArguments, Dictionary`2 outputArguments)
Did you have any suggestion to solve this problem ?.
Best regards.