Lollalol’s solution solved my problem.
Go to your widget blueprint, add a variable called “Owner” (of whatever type owns it, HeroCharacter?) and either expose it or create a setter function for it.
In the blueprint that you’re creating the widget class and adding to the viewport: after you construct the widget class, drag its’ output, and right-click to either set the “Owner” variable (either exposed, or using the setter if you created one).
Go back to your widget blueprint, and instead of using the “Owning Player whatever” node, drag out your “Owner” variable, and use that instead.