For example you want to load http://sunnythedeveloper.epizy.com/ then you simply put the url in GoToUrl block.
There is internet so you were able to access it but since it redirects to http://sunnythedeveloper.epizy.com/i=1 and suddenly internet disconnects then your above block will fail.
Although, you still have an option to compare original url with failing url.
Otherwise, you can always use the OnDiconnect event of the following extension: