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