I am not able to login to acme site, even though the output panel shows login successful. on the page, wrong id or password box appears.
Type same credentials manually and login once.
And also UIpath recommend to use IE browser to work with ACME data and it will identify pop ups easily.
The error simply means that there is a selector issue.
And like what @lakshman suggested, please use Internet Explorer for this activity.
@Anky I Believe, it is trying to match the title of the window to SHA1Online, but actual title has some additional words. Try to remove title selector and execute.
Edit selector and uncheck Title.