Error in Workflow Instance Extension Manager when running automation


I have an automation that generates an error when executing sometimes (not always)

I get the errors of the image

other times the debugging starts but stays there:

  • I have tried updating the dependencies

  • I have tried reinstalling the bot

  • I have tried reinstalling UiPath

  • I have also tried downloading some recommended packages
    -I have tried to use other elements, for example, not using the AppCheckState but when I run it again I get the error in the following element of the flow

    but none have worked.

I am very grateful to those who can help me.


Welcome to the Community!

TargetInvocationException masks the real exception by telling you that it crashed during “a method invocation”, usually through something.Invoke.

What you have to do is look at the InnerException property of the exception object (the TargetInvocationException object). I am not sure on what activity you are getting this error, but whenever you are getting that time null value passed for a parameter which is mandatory for that activity.


Thanks, but I can’t catch the real exception because the automation never starts.
When I press Run, Run File or Debug, the Error Validations are done and immediately the errors that I show in the screenshot appear.

Sometimes it starts without problems and finishes all the automation without any error, other times it indicates an error about different activities and/or flows, for example: in one execution it can show me an error in flow A in the Click activity, then in another execution It shows me an error in flow A but in the Type Into activity and in another execution I could not show errors in flow A.

I think it could be the new activities of modern design like Check app state or Use app/browser