4.8 preview 1 - Action Interface "would always fail"

http://puu.sh/hIt6n/74c853f89d.png

So I get this error after going over to preview 1. It have worked until now, even with the compile error… But why do i get that warning still?

I believe this is an erroneous warning that will be removed for the next preview build: Unreal Engine 4.8 Preview - Announcements - Epic Developer Community Forums