How can I ensure my Gameplay Ability System Attributes will be visible to Gameplay Effect Modifiers?

I have created the following attribute set and I would like to be able to make a gameplay effect to reduce the health .etc. This attribute set has been applied to my Ability Component but it is not visible in the list of Attributes in the Gameplay Effect.
Is there an issue with my C++ or is it something else?



This solution, deleting the Binaries, worked for me