Just to clarify, my issue is slightly different. I was able to go inside the edit mode and do all the none-map-related edits, but the maps never load.
Below paragraphs are off the topic. I do think your issue is a valuable topic for another thread because it has been bothering me too.
I ran into the issue a lot lately. This is very frustrating because when I ran into this, it basically means I won't be able to access this anymore and I have to start over. One time, I got lucky as I was still able to duplicate the story when I am in the reading mode. When I clicked duplicate button from top, it sent me directly into the edit mode. However, most of the time, duplicate action led to the same page as your screenshot.
After running into this for a few times, I kinda figure out what triggers it (at least in my case).
What happened to me was that my story has a lot of map actions which refer to certain bookmarks I created in web maps. I noticed that whenever I published my story with a bookmark links broken (due to the removal of bookmark or web map), I won't be able to go back to edit mode. For example, if I set up a slide with bunch of working map actions. Then I decided to remove the web map for the time being and come back later. If I publish the story map with map removed but without those map actions removed, I am 100% running into an error when I try to edit the published story later.
After that, I have been extremely cautions with map action and back up story map draft once in a while. Every time I discovered that I need to make change to a web maps which involves removing a layer that's being used, I make sure I fix all the map actions before I publish it again. If I must publish the story for the moment with some web map changes to be taken care of later, I would just remove all the map action for the time and added them back later.
I think this needs to be fixed. We should be allowed to have broken map action when we try to edit the story. Otherwise, please don't let us save our story if Esri detects anything that would trigger this event. As I mentioned, since we cannot edit the story to fix the error, that piece of project is trapped and I had to recreate the whole thing again.