Hi Naomi, in the last release of ArcGIS Online, the feature service team added a new group of servers to handle additional users. This new group did not get whitelisted in our JavaScript API until after the release. Because of this, the story map cannot communicate correctly with those servers and the story fails halfway through the creation process. We have a fix in our code and have added additional measures to make sure this does not happen again in the future. Unfortunately, these fixes will not be rolled until the next ArcGIS Online update (scheduled for September).
Until then, our team has created a temporary URL that you can use to create a new crowdsource stories. This bug is only an issue in the initial app creation step of the builder. Once you create the items with this temporary URL, you will be redirected to the app on ArcGIS Online which you can edit and share as you normally would.
Here's the app you can use to create your stories:
https://storymap-crowdsource.surge.sh/index.html?fromScratch