I have created two nodes and connected the 1st node with the 2nd node in regtest mode . Now when I make the getblocktemplate command using bitcoin-cli . It fails with bitcoin is downloading the block.
 
Bitcoin core vs v0.16

_admin1@root:~/Projects/bitcoin$ ./src/bitcoin-cli -regtest -port=8333 -rpcport=8332 -rpcuser=test -rpcpassword=test getconnectioncount_
**1**
_admin1@root:~/Projects/bitcoin$ ./src/bitcoin-cli -regtest -port=8333 -rpcport=8332 -rpcuser=test -rpcpassword=test getblocktemplate_
**error code: -10
error message:
Bitcoin is downloading blocks.**
"An error is returned if not enough transactions and blocks\n"
            "have been observed to make an estimate for any number of blocks.\n"
                },
                RPCExamples{
                    HelpExampleCli("estimatesmartfee", "6")
                },
            }.ToString());
    RPCTypeCheck(request.params, {UniValue::VNUM, UniValue::VSTR});
    RPCTypeCheckArgument(request.params[0], UniValue::VNUM);
    unsigned int max_target = ::feeEstimator.HighestTargetTracked(FeeEstimateHorizon::LONG_HALFLIFE);
    unsigned int conf_target = ParseConfirmTarget(request.params[0], max_target);
    bool conservative = true;
    if (!request.params[1].isNull()) {
        FeeEstimateMode fee_mode;
        if (!FeeModeFromString(request.params[1].get_str(), fee_mode)) {
            throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid estimate_mode parameter");
        }
        if (fee_mode == FeeEstimateMode::ECONOMICAL) conservative = false;
    }
    UniValue result(UniValue::VOBJ);
    UniValue errors(UniValue::VARR);
    FeeCalculation feeCalc;
    CFeeRate feeRate = ::feeEstimator.estimateSmartFee(conf_target, &feeCalc, conservative);
    if (feeRate != CFeeRate(0)) {
        result.pushKV("feerate", ValueFromAmount(feeRate.GetFeePerK()));
    } else {
        errors.push_back("Insufficient data or no feerate found");
        result.pushKV("errors", errors);
    }
    result.pushKV("blocks", feeCalc.returnedTarget);