The fix is obvious. The value MAX_BLOCK_SIZE is too low. Why you have set it to 10K ?
The POS is not working as well because of this.
ERROR: AcceptBlock() : reject proof-of-stake at height 6489
ERROR: ProcessBlock() : AcceptBlock FAILED
ERROR: CheckStake() : ProcessBlock, block not accepted
ERROR: CreateCoinStake : exceeded coinstake size limit
If the dev is still interested fixing his coin:
MAX_BLOCK_SIZE should be raised to
MAX_BLOCK_SIZE = 1000000
, but this will make an immediate fork, so you will need to synchronize the update, with the pools and the exchanges. Of course you can also make a delayed fork. Contact me if you need more info.