I have also, just this moment, come across the very same issue. I tried to move all the elements from the original file (which was created pre update) to a fresh file but to no luck; the issue followed me over to the new location. Trying to isolate the issue, I began deleting different element until I discovered that the cause of the issue lied with the images that had been imported through the in-built 'Stock' tool. Removing them, I was able to fix the issue.
Edit: I should also add, this only happened after I copied the original file to a new location, changed its name, and then tried to save changes to that new file. Going back to the old file, I am able to save change it it without issue.
Hopefully this help fix the bug.
All the best,