CheckProofOfWork() Linux error on old altcoins
That error simply means that the block is invalid as the proof of work is incorrect. That has nothing to do with OpenSSL versions. The difficulty of a block is specified by the nBits field of the block header, and the block header must hash to a hash that is less than nBits. What is happening here is that the block hash is not less than the nBits, so the block is invalid.