Zcash Withdraw returns transaction returns failure

In my site we are integrating zcash cryptocurrency withdraw process. we implemented with php via sendtoaddress json rpc wallet for send zcash coin from one address to another.

Error Message which i got was

Error: The transaction was rejected! This might happen if some of the coins in your wallet were already spent, such as if you used a copy of wallet.dat and coins were spent in the copy but not marked as spent here.

please find the attachment