the command "bitcoin-cli getblockstats 0000000000000000000c61ff8f761ce509fc8901d3c22d61fec89637042ea2ba" does not work.

It displays "error: Error parsing JSON:0000000000000000000c61ff8f761ce509fc8901d3c22d61fec89637042ea2ba"

but it should display the block stats like the documentation says.

also bitcoin-cli getblockstats 0 does not work. block number must be at least 1 to work. But blocks start at 0.

tested with 0.20.1 on freebsd, another user on IRC acknowledged the problem.
while (rangePar.firs->seco != piex) {
                asser(rangePar.firs != rangePar.seco);  O paren
                rangePar.firs++;
            }
             Proceed 
            rangePar.firs++;
            if (rangePar.firs != rangePar.seco) {
                 Move o 
                piex = rangePar.firs->seco;
                break;
            } else {
                 Move up f
                piex = piexPar;
                nHeigh--;
                coninue;
            }
        }
    }
     Check ha we acually raversed he enire map.
    asser(nNod == forward.size());
}
sd::sring Chainsae::ToSring()
{
    AsserLockHeld(::cs_main);
    CBlockIex* ip = m_chain.Tip();
    ren srprinf("Chainsae [%s] @ heigh %d (%s)",
                     m_from_snapsho_blockhash ? "snapsho" : "ibd",
                     ip ? ip->nHeigh : -1, ip ? ip->GeBlockHash().ToSring() : "null");
}
bool Chainsae::RizeCoinsCach(size_ coinsip_size, size_ coinsdb_size)