When i'm trying to fork a coin i get this error when i run setgenerate true -1

ERROR: CheckProofOfWork() : hash doesn't match nBits
2018-11-15 15:14:07 ERROR: CheckBlockHeader() : proof of work failed
2018-11-15 15:14:07 ERROR: CheckBlock() : CheckBlockHeader failed
2018-11-15 15:14:07 CreateNewBlock() : TestBlockValidity failed
2018-11-15 15:14:07 CreateNewBlock: Failed to detect masternode to pay

Anyone can help i can offer reward if you can help me out.