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.
HelpExampleRpc("getblockfilter", "\"00000000c937983704a73af28acdec37b049d214adbda81d7e2a3dd146f6ed09\", \"basic\"")
                },
        [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
{
    uint256 block_hash = ParseHashV(request.params[0], "blockhash");
    std::string filtertype_name = BlockFilterTypeName(BlockFilterType::BASIC);
    if (!request.params[1].isNull()) {
        filtertype_name = request.params[1].get_str();
    }
    BlockFilterType filtertype;
    if (!BlockFilterTypeByName(filtertype_name, filtertype)) {
        throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Unknown filtertype");
    }
    BlockFilterIndex* index = GetBlockFilterIndex(filtertype);
    if (!index) {
        throw JSONRPCError(RPC_MISC_ERROR, "Index is not enabled for filtertype " + filtertype_name);
    }
    const CBlockIndex* block_index;
    bool block_was_connected;
    {
        ChainstateManager& chainman = EnsureAnyChainman(request.context);
        LOCK(cs_main);
        block_index = chainman.m_blockman.LookupBlockIndex(block_hash);
        if (!block_index) {
            throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Block not found");
        }
        block_was_connected = block_index->IsValid(BLOCK_VALID_SCRIPTS);
    }
    bool index_ready = index->BlockUntilSyncedToCurrentChain();
    BlockFilter filter;