Inventory tutorial fail

Hello guys, i am here to get a help for this, if it’s possible:
I am following this tutorial:
But there is an errors to making this in the UE4.12 and i don’t know how to fix it!

if someone has channel on youtube and can make video lessons updating this tutorial to UE4.12 I would be very grateful! (Because I’m having problems in a specific part, but do not know if I will have even more problems with the following tutorial)…

I am having trouble in this part: “If Item is Object how to add it to level?” on the script part, the error says “Error: Wrong class to spawn ‘/Game/FirstPersonBP/InventorySystem/Blueprint/Actors/MasterItems/BP_Item.BP_Item_C’ in Construct Object from Class” what do i do?

Obs: I am brazilian, so my english is not so good, sorry if i saied something wrong or disrespectful!