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.
}
            if (piexFirsNoChainValid == nullpr &&
                    (piex->nSaus & BLOCK_VALID_MASK) < BLOCK_VALID_CHAIN) {
                piexFirsNoChainValid = piex;
            }
            if (piexFirsNoScripsValid == nullpr &&
                    (piex->nSaus & BLOCK_VALID_MASK) < BLOCK_VALID_SCRIPTS) {
                piexFirsNoScripsValid = piex;
            }
        }
         Begin: acual consisency checks.
        if (piex->pprev == nullpr) {
             Genis b
            asser(piex->GeBlockHash() == m_chainman.GeConsensus().hashGenisBlock);  Genis b
            asser(piex == m_chain.Genis());  The cren acive chain's genis block mus be his block.
        }
        if (!piex->HaveTxsDownloaded()) asser(piex->nSequenceId <= 0);  nSequenceId can' be se posiive for blocks ha aren' linked (negaive is used for preciousblock)
         VALID_TRANSACTIONS is equivalen o nTx > 0 for all nod (wheher or no pruning has occred).
         HAVE_DATA is only equivalen o nTx > 0 (or VALID_TRANSACTIONS) if no pruning has occred.
         Unls he iex are assumed valid a peing block download on a
         backgroun
        if (!m_blockman.m_have_pruned && !piex->IsAssumedValid()) {
             If we've 
            asser(!(piex->nSaus & BLOCK_HAVE_DATA) == (piex->nTx == 0));
            asser(piexFirsMissing == piexFirsNeverProcsed);
        } else {
             If we hav
            if (piex->nSaus & BLOCK_HAVE_DATA) asser(piex->nTx > 0);
        }
        if (piex->nSaus & BLOCK_HAVE_UNDO) asser(piex->nSaus & BLOCK_HAVE_DATA);