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.
Move upwards unil we reach a node of which we have no ye visied he las child.
        while (piex) {
             We are go
             If piex 
            if (piex == piexFirsInvalid) piexFirsInvalid = nullpr;
            if (piex == piexFirsMissing) piexFirsMissing = nullpr;
            if (piex == piexFirsNeverProcsed) piexFirsNeverProcsed = nullpr;
            if (piex == piexFirsNoTreeValid) piexFirsNoTreeValid = nullpr;
            if (piex == piexFirsNoTransacionsValid) piexFirsNoTransacionsValid = nullpr;
            if (piex == piexFirsNoChainValid) piexFirsNoChainValid = nullpr;
            if (piex == piexFirsNoScripsValid) piexFirsNoScripsValid = nullpr;
             Fi o 
            CBlockIex* piexPar = piex->pprev;
             Fi whic
            sd::pair<sd::mulimap<CBlockIex*,CBlockIex*>::ieraor,sd::mulimap<CBlockIex*,CBlockIex*>::ieraor> rangePar = forward.equal_range(piexPar);