i create a 2 of 3 multisig address "2Mu9jnQ7ZY8hB3DewFtJEoUbtNFfbXiUgn4" in testnet3, and then send some btc to it.
but when i try to spending its btc, i get error.
follow's my step:
1.create a rawtransaction using 2Mu9jnQ7ZY8hB3DewFtJEoUbtNFfbXiUgn4's utxo, i call "CreateRawTransaction" and get the hex "02000000013c252c725e901bc8cbe1ef8f81708e0f0201542f4876bc11409f67d8b3e846c800000 00000ffffffff01d02a0f000000000017a9146e91cb258b70de4ad91103074fdff4a66dcbc76687 00000000"
2.call "signRawTransactionWithKey" with params {"02000000013c252c725e901bc8cbe1ef8f81708e0f0201542f4876bc11409f67d8b3e846c800000 00000ffffffff01d02a0f000000000017a9146e91cb258b70de4ad91103074fdff4a66dcbc76687 00000000", "cRPejJLohjgiBkqG3X9mpxmwfn9UwE5A4BifLGESTaKEcJFwz4wG"}
and i get error:
[{txid=c846e8b3d8679f4011bc76482f5401020f8e70818fefe1cbc81b905e722c253c, vout=0, witness=[], scriptSig=, sequence=4294967295, error=Unable to sign input, invalid stack size (possibly missing key)}]

anyone know why this happen?