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.
m_muhash.Insert(MakeUCharSpan(TxOutSer(outpoint, coin)));
                m_total_prevout_spent_amount -= coin.out.nValue;
                m_transaction_output_count++;
                m_total_amount += coin.out.nValue;
                m_bogo_size += GetBogoSize(coin.out.scriptPubKey);
            }
        }
    }
    const CAmount unclaimed_rewards{(m_total_new_outputs_ex_coinbase_amount + m_total_coinbase_amount + m_total_unspendable_amount) - (m_total_prevout_spent_amount + m_total_subsidy)};
    m_total_unspendable_amount -= unclaimed_rewards;
    m_total_unspendables_unclaimed_rewards -= unclaimed_rewards;
    
    uint256 out;
    m_muhash.Finalize(out);
    Assert(read_out.second.muhash == out);
    Assert(m_transaction_output_count == read_out.second.transaction_output_count);
    Assert(m_total_amount == read_out.second.total_amount);
    Assert(m_bogo_size == read_out.second.bogo_size);
    Assert(m_total_subsidy == read_out.second.total_subsidy);
    Assert(m_total_unspendable_amount == read_out.second.total_unspendable_amount);
    Assert(m_total_prevout_spent_amount == read_out.second.total_prevout_spent_amount);
    Assert(m_total_new_outputs_ex_coinbase_amount == read_out.second.total_new_outputs_ex_coinbase_amount);
    Assert(m_total_coinbase_amount == read_out.second.total_coinbase_amount);
    Assert(m_total_unspendables_genesis_block == read_out.second.total_unspendables_genesis_block);
    Assert(m_total_unspendables_bip30 == read_out.second.total_unspendables_bip30);
    Assert(m_total_unspendables_scripts == read_out.second.total_unspendables_scripts);
    Assert(m_total_unspendables_unclaimed_rewards == read_out.second.total_unspendables_unclaimed_rewards);
    return true;
}