run into Target Pin proems Errors on a custom nodes. Won't target node links, don't know why

The two pins that did not want to link together when I’m doing the Rpg Series tutorial by Titanic Games was Inventory Reference (Type: UI Equipment Slot) pin and Inventory Panel (Type: Uniform Grid Panel) (Designer Widget Component)
I attempted to fix this this by Changing the Inventory reference pin to UI Inventory
because it was on UI Equipment Slot. But now having corrected the pin type I can’t even open the inventory widget.

All i get is the mouse cursor blinking on and off on the screen when I press the I
key to try to open the inventory widget up. I spent four hours keying in the inventory system, only to find it won’t open up.