Calculate health Error

I am fairly new to unreal engine and going through the tutorials. I skipped the C++ Part 5 and did a blueprint instead, (Tried to make C++ Crashed the whole projected)

At “BP Twin Stick Shooter: Damaging the Enemy | 11 | v4.8 Tutorial Series | Unreal Engine” we are making Event Affect Health. When I right click I get “Call function” CaculateHealth instead for a function. They look almost the same but I get this error when I compile: “This blueprint (self) is not a Base_Character_C, therefore “Target” must have a connection” ( Timestamp - BP Twin Stick Shooter )