Possibly it is because the "Previous Tx" is not yet confirmed, or is already spent by another transaction. If so, you can manually create the transaction and use your Private Key to sign it and then broadcast.
Can you post the TxId of the transaction that you are trying to spend?
i try to send payment manually, but i get this error and not able to send any payment.
i don't know what TxID will be while new payment not yet able to send.
i find my error code here [192230192, 192237304] :
https://blockchain.info/rejectedf27bfc80a1dd9774506fe41a4... Previous Tx is unspendable [192230192, 192237304] 2016-11-24 08:53:40
Thanks for your reply!