I decided I wanted to peel and claim a 0.5BTC casascius coin. I am using electrum to try and sweep the wallet but am getting the error "no inputs found". When I import the private it key it gives me a balance of 0 and a receiving address entirely different from what the coin has on it. The analyzer says the coin is still funded. I bought it in 2013. Anyone have any idea what is going on or did I somehow get duped 4 years ago? Really needed the money .

Thanks for any help!