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 (!m_db->Read(DB_MUHASH, m_muhash)) {
        
        
        
        if (m_db->Exists(DB_MUHASH)) {
            return error("%s: Cannot read current %s state; index may be corrupted",
                         __func__, GetName());