There are a few things that could cause the error. Please check the Selector property of the Type Into activity that is causing the error. Try and replace text that is too specific with wildcards and also try removing attributes that are not needed (for example, it’s possible that the selector contains the “app” attribute with the value of a browser application, which prevents it from working in other browsers). If you could provide more details that would be great.
How did you open the web page? If you inserted the url in the adress bar you may need to add an Attach Window activity (before the TypeInto activity used for the username) in order to attach to the new window.
I thought maybe you hit the “Record” button, then typed in the url in a new tab and hit enter to open the web page, a transition which would need to be put in an Attach Browser activity preferably or Attach Window. Using Open Browser in this case should be enough though. I’m afraid I don’t know what is causing the error. If the web site you are trying to log in to is public please share the link so I can try recording the steps. Maybe sharing this part of your process would also enable others to find the cause for the error.