I bought coins some time ago, installed masternode, but get an error about previous block invalid -

2018-07-05 06:38:37 ERROR: ConnectBlock() : reward pays too much (actual=74.9999896 vs limit=60.00)
2018-07-05 06:38:37 InvalidChainFound: invalid block=6829596217cb52aa018fa56195c1b6de41ef6c3a28f229cfa5a3bb15d947bdbe  height=50500  log2_work=65.63823  date=2018-06-16 18:36:26
2018-07-05 06:38:37 InvalidChainFound:  current best=3ca88d198b657f7c5927b0174b7bbc6d80da50e88c9c9902da5473832da081e9  height=50499  log2_work=65.638151  date=2018-06-16 18:35:52
2018-07-05 06:38:37 ERROR: ConnectTip() : ConnectBlock 6829596217cb52aa018fa56195c1b6de41ef6c3a28f229cfa5a3bb15d947bdbe failed
2018-07-05 06:38:37 InvalidChainFound: invalid block=6829596217cb52aa018fa56195c1b6de41ef6c3a28f229cfa5a3bb15d947bdbe  height=50500  log2_work=65.63823  date=2018-06-16 18:36:26
2018-07-05 06:38:37 InvalidChainFound:  current best=3ca88d198b657f7c5927b0174b7bbc6d80da50e88c9c9902da5473832da081e9  height=50499  log2_work=65.638151  date=2018-06-16 18:35:52
2018-07-05 06:38:37 ProcessNewBlock : ACCEPTED
2018-07-05 06:38:37 ProcessNewBlock : ACCEPTED
2018-07-05 06:38:37 ProcessNewBlock : ACCEPTED
2018-07-05 06:38:37 ProcessNewBlock : ACCEPTED
2018-07-05 06:38:37 ProcessNewBlock : ACCEPTED
2018-07-05 06:38:37 ProcessNewBlock : ACCEPTED
2018-07-05 06:38:37 ProcessNewBlock : ACCEPTED
2018-07-05 06:38:37 ProcessNewBlock : ACCEPTED
2018-07-05 06:38:37 ProcessNewBlock : ACCEPTED
2018-07-05 06:38:37 ERROR: AcceptBlockHeader : block is marked invalid
2018-07-05 06:38:37 ERROR: ProcessNewBlock : AcceptBlock FAILED
2018-07-05 06:38:37 ProcessNewBlock : ACCEPTED
2018-07-05 06:38:37 ProcessNewBlock : ACCEPTED
2018-07-05 06:38:37 ProcessNewBlock : ACCEPTED
2018-07-05 06:38:37 ERROR: AcceptBlock : prev block invalid
2018-07-05 06:38:37 ERROR: ProcessNewBlock : AcceptBlock FAILED
2018-07-05 06:38:37 ProcessNewBlock : ACCEPTED
2018-07-05 06:38:37 ERROR: AcceptBlockHeader : block is marked invalid
2018-07-05 06:38:37 ERROR: ProcessNewBlock : AcceptBlock FAILED
2018-07-05 06:38:37 ProcessNewBlock : ACCEPTED
2018-07-05 06:38:37 ProcessNewBlock : ACCEPTED
2018-07-05 06:38:37 ERROR: AcceptBlockHeader : block is marked invalid
2018-07-05 06:38:37 ERROR: ProcessNewBlock : AcceptBlock FAILED
2018-07-05 06:38:37 ProcessNewBlock : ACCEPTED
2018-07-05 06:38:37 ProcessNewBlock : ACCEPTED
2018-07-05 06:38:37 ERROR: AcceptBlockHeader : block is marked invalid
2018-07-05 06:38:37 ERROR: ProcessNewBlock : AcceptBlock FAILED
2018-07-05 06:38:37 ERROR: AcceptBlock : prev block invalid
2018-07-05 06:38:37 ERROR: ProcessNewBlock : AcceptBlock FAILED


Anyone know how to correct it???