Suppose that in order to avoid loss in transmission, a secret key encryption scheme $(Gen, Enc, Dec)$ is modified to be $(Gen, Enc', Dec')$, such that the message m is encrypted independently three times as $Enc'(m)=(c_1,c_2,c_3)$, each $c_i=Enc(m)$.
For decryption, the 3 transmitted ciphertexts are decrypted using $Dec$. If at least 2 recover to the same message, that message is output as the decryption. Otherwise, an error message will be output.
So, I am wondering if $(Gen, Enc, Dec)$ is indistinguishable under a chosen-ciphertext-attack (IND-CCA), why isn't $(Gen, Enc', Dec')$ IND-CCA, too? Is that because there is the possibility that we may receive the error message? I mean $(Gen, Enc', Dec')$ uses the same $Enc$ and $Dec$, why doesn't it inherit the IND-CCA property?