In this edit the VisualEditor seems to have introduced a ref named ":1036" but no definition for it, as well as two empty refs (<ref /><ref />).
Topic on VisualEditor/Feedback
Does this look like phab:T94712 which links to phab:T209493 to you?
I'm not sure whether it has the same underlying cause as T94712, but the effect is different and IMO more severe, as the edit I reported left the page in a state with several invalid references (two empty and three undefined).
Matma Rex, you might want to take a quick look at this.
Looks like the same issue as T300066 to me.
This is meant to be fixed now.