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.
{
    
    AssertLockNotHeld(cs_main); 
    UniValue result(UniValue::VOBJ);
    result.pushKV("hash", blockindex->GetBlockHash().GetHex());
    const CBlockIndex* pnext;
    int confirmations = ComputeNextBlockAndDepth(tip, blockindex, pnext);
    result.pushKV("confirmations", confirmations);
    result.pushKV("height", blockindex->nHeight);
    result.pushKV("version", blockindex->nVersion);
    result.pushKV("versionHex", strprintf("%08x", blockindex->nVersion));
    result.pushKV("merkleroot", blockindex->hashMerkleRoot.GetHex());
    result.pushKV("time", (int64_t)blockindex->nTime);
    result.pushKV("mediantime", (int64_t)blockindex->GetMedianTimePast());
    result.pushKV("nonce", (uint64_t)blockindex->nNonce);
    result.pushKV("bits", strprintf("%08x", blockindex->nBits));
    result.pushKV("difficulty", GetDifficulty(blockindex));
    result.pushKV("chainwork", blockindex->nChainWork.GetHex());
    result.pushKV("nTx", (uint64_t)blockindex->nTx);
    if (blockindex->pprev)
        result.pushKV("previousblockhash", blockindex->pprev->GetBlockHash().GetHex());
    if (pnext)
        result.pushKV("nextblockhash", pnext->GetBlockHash().GetHex());
    return result;
}
UniValue blockToJSON(BlockManager& blockman, const CBlock& block, const CBlockIndex* tip, const CBlockIndex* blockindex, TxVerbosity verbosity)