I created a workflow a few days ago. Comeback to it today and I have a blank workflow. I can see my last execution, but cannot do anything with it?
I have logged out and logged back in again. I have just upgraded as well, but no joy.
I can see the last execution I created. See this image
Just speculating, but when this has happened to me, I discovered (remembered) that I had the same workflow open in multiple browser tabs and:
Edited, saved, and executed everything in the “2nd” tab
Later… closed the “1st” tab (with blank content), which prompted to me to “Save”, and overwrote all the work from the “2nd” tab.
You may need to just reconstruct your workflow and be careful about having multiple tabs/browser-windows open (assuming that is also how this happened for you). I (try to) look at this kind of thing as an opportunity to do things better than I did the first time.