Once upon a time in Springfield part 8

Both are placed

Try going to Friends List & back (to refresh/resync your game), or if that doesn't work, log out & back in.
Otherwise you'll probably have to lodge a ticket with EA Support (or wait for a patch).

You could try storing the Rock and taking it back out of inventory.

tcmcanuck wrote:
In part 8 of the main quest line it says to earn both prizes from day 1 in the general store. I earned the rock before part 8 started and earned the horse during part 8. It is only registering that I have one. Any suggestions how to progress?

I'm also having this problem. I've tried storing both items, going to Krustyland, logging out completely and logging back in - nothing has worked. I contacted EA who asked me how to fix it and whether I need donuts - there doesn't even seem to be a way to complete it with donuts. Did you ever manage to resolve this, and if so what did you do?

I'm having the exact same problem.

Tried uninstalling/reinstalling the game, but still doesn't work.