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.
LogPrintf("scanblocks RPC aborted at height %d.\n", block->nHeight);
                break;
            }
            const CBlockIndex* next = nullptr;
            {
                LOCK(cs_main);
                CChain& active_chain = chainman.ActiveChain();
                next = active_chain.Next(block);
                if (block == stop_block) next = nullptr;
            }
            if (start_index->nHeight + amount_per_chunk == block->nHeight || next == nullptr) {
                LogPrint(BCLog::RPC, "Fetching blockfilters from height %d to height %d.\n", start_index->nHeight, block->nHeight);
                if (index->LookupFilterRange(start_index->nHeight, block, filters)) {
                    for (const BlockFilter& filter : filters) {
                        
                        if (filter.GetFilter().MatchAny(needle_set)) {
                            blocks.push_back(filter.GetBlockHash().GetHex());
                            LogPrint(BCLog::RPC, "scanblocks: found match in %s\n", filter.GetBlockHash().GetHex());
                        }
                    }
                }
                start_index = block;
                
                int blocks_processed = block->nHeight - start_block->nHeight;
                if (total_blocks_to_process > 0) { 
                    g_scanfilter_progress = (int)(100.0 / total_blocks_to_process * blocks_processed);
                } else {
                    g_scanfilter_progress = 100;
                }
                g_scanfilter_progress_height = block->nHeight;