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.**
std::chrono::steady_clock::time_point checktxtime;
        unsigned int nTransactionsUpdatedLastLP;
        if (lpval.isStr())
        {
            
            std::string lpstr = lpval.get_str();
            hashWatchedChain = ParseHashV(lpstr.substr(0, 64), "longpollid");
            nTransactionsUpdatedLastLP = atoi64(lpstr.substr(64));
        }
        else
        {
            
            hashWatchedChain = chainActive.Tip()->GetBlockHash();
            nTransactionsUpdatedLastLP = nTransactionsUpdatedLast;
        }
        
        LEAVE_CRITICAL_SECTION(cs_main);
        {
            checktxtime = std::chrono::steady_clock::now() + std::chrono::minutes(1);
            WAIT_LOCK(g_best_block_mutex, lock);
            while (g_best_block == hashWatchedChain && IsRPCRunning())
            {
                if (g_best_block_cv.wait_until(lock, checktxtime) == std::cv_status::timeout)
                {
                    
                    if (mempool.GetTransactionsUpdated() != nTransactionsUpdatedLastLP)
                        break;
                    checktxtime += std::chrono::seconds(10);
                }
            }