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.
ret_all.pushKV("swtotal_size", swtotal_size);
    ret_all.pushKV("swtotal_weight", swtotal_weight);
    ret_all.pushKV("swtxs", swtxs);
    ret_all.pushKV("time", pindex.GetBlockTime());
    ret_all.pushKV("total_out", total_out);
    ret_all.pushKV("total_size", total_size);
    ret_all.pushKV("total_weight", total_weight);
    ret_all.pushKV("totalfee", totalfee);
    ret_all.pushKV("txs", (int64_t)block.vtx.size());
    ret_all.pushKV("utxo_increase", outputs - inputs);
    ret_all.pushKV("utxo_size_inc", utxo_size_inc);
    if (do_all) {
        return ret_all;
    }
    UniValue ret(UniValue::VOBJ);
    for (const std::string& stat : stats) {
        const UniValue& value = ret_all[stat];
        if (value.isNull()) {
            throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("Invalid selected statistic '%s'", stat));
        }
        ret.pushKV(stat, value);
    }
    return ret;
},
    };
}
namespace {
bool FindScriptPubKey(std::atomic<int>& scan_progress, const std::atomic<bool>& should_abort, int64_t& count, CCoinsViewCursor* cursor, const std::set<CScript>& needles, std::map<COutPoint, Coin>& out_results, std::function<void()>& interruption_point)
{
    scan_progress = 0;