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.
}
            block = next;
        }
        ret.pushKV("from_height", start_block->nHeight);
        ret.pushKV("to_height", g_scanfilter_progress_height.load());
        ret.pushKV("relevant_blocks", blocks);
    }
    else {
        throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("Invalid action '%s'", request.params[0].get_str()));
    }
    return ret;
},
    };
}
static RPCHelpMan getblockfilter()
{
    return RPCHelpMan{"getblockfilter",
                "\nRetrieve a BIP 157 content filter for a particular block.\n",
                {
                    {"blockhash", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "The hash of the block"},
                    {"filtertype", RPCArg::Type::STR, RPCArg::Default{BlockFilterTypeName(BlockFilterType::BASIC)}, "The type name of the filter"},
                },
                RPCResult{
                    RPCResult::Type::OBJ, "", "",
                    {
                        {RPCResult::Type::STR_HEX, "filter", "the hex-encoded filter data"},
                        {RPCResult::Type::STR_HEX, "header", "the hex-encoded filter header"},
                    }},
                RPCExamples{
                    HelpExampleCli("getblockfilter", "\"00000000c937983704a73af28acdec37b049d214adbda81d7e2a3dd146f6ed09\" \"basic\"") +