Error check

src/wallet/rpcwallet.cpp

@@ -4113,6 +4113,9 @@ UniValue z_sendmany(const UniValue& params, bool fHelp)
                     if ( fromSprout || toSprout )
                         throw JSONRPCError(RPC_INVALID_PARAMETER,"Sprout usage has expired");
                 }
+                if ( toSapling && ASSETCHAINS_SYMBOL[0] == 0 )
+                    throw JSONRPCError(RPC_INVALID_PARAMETER,"Sprout usage will expire soon");
+   
                 // If we are sending from a shielded address, all recipient
                 // shielded addresses must be of the same type.
                 if ((fromSprout && toSapling) || (fromSapling && toSprout)) {