We have been provided a customized story map and our intention is to make some slight alterations and updates to it. We have published this to the following URL: DDOT AlleyPalooza 3.0 Story
I've added it to my AGO account, registered and shared it publicly within AGO here: http://dcgis.maps.arcgis.com/home/item.html?id=bbf0653779ae4191bd62dddb9e4dc507#overview
Unfortunately, I can't seem to get it to allow me to configure using the built-in configuration tool. I'm prompted to authenticate (even though I'm already logged in) and then get an error message after trying to log in:
This is my first time ever customizing someone else's customized template. Any ideas?