Smart Key not working after radio replacement

I just purchased a 2009 Prius and I decided to replace the radio. The smart key system was working until the radio was replaced but I have no idea how replacing the radio could have caused this. After it quit working, I reinstalled the original factory radio and the problem is still happening. The smart key works for the doors but it will not start, instead the 'key not found' comes on. The car will start when I put the key into the slot.

Thanks in advance,

Travis