How do I call a interface from a AI Task?

Was following this tutorial

It's for a slightly older version of Unreal Engine and this isn't the first hiccup in it that I experienced, but the first one that I couldn't find an answer to.

The sum of it is that it applies damage to a character using AI behavior trees and connecting them to a interface. I create the task that draws a line to the player and damages them on contact. I have it on debug so I can see the line is fine and I even added a print string after that so I’d know that everything is running until then. However the last bit is connecting the interface.

The interface is suppose to subtract health and then play a string, but I know it isn’t working just the string isn’t popping up. The string that plays after the interface pops up but not the one in the interface. What is going on?

Here is the character base that has the interface http://i.imgur.com/elMCk1q.png

This is the character. It inherited the health interface. http://i.imgur.com/HpQxW2L.png

Here is the attack task for the enemy AI. It sends a message to the health interface when it hits the player character.

And finally here’s the debug line showing the trace from the enemy to the player character.