Need some help with Endless Runner in BP

I followed the endless runner tutorial here? https://docs.unrealengine.com/latest/INT/Videos/PLZlv_N0_O1gbY4FN8pZuEPVC9PzQThNn1/3om6yJiYMcg/index.html. I followed the entire set of videos, but I am running into an error that I can’t seem to figure out. First of all, in the second video in the series where he is setting up the floor tile spawning…In his function, he spawns the actor from class, BP_FloorTile. Then he casts to the BP_FloorTile. When I do this on my end, I get a warning when I compile that states it is already a BP_FloorTile, and does not need to cast. So, I deleted the cast node, and drug off the pin to get the “Add Floor Tile” function instead. When I compile and test, the game does not open. Instead, I get this:

(My floor tile BP is called BP_Empty).

There is no coding currently in the construction script, and at this point in the series, he has not added anything to the construction script. Yet, when I follow the tutorial to a tee, I get this. What is going on here and how do I fix it?