In my debug log many error:
2017-09-08 15:18:21 ERROR: CheckBlock() : Couldn't find masternode/budget payment
2017-09-08 15:18:21 ERROR: ProcessNewBlock: CheckBlock FAILED
2017-09-08 15:18:21 Misbehaving: 75.130.162.248:9399 (6278500 -> 6278600)
2017-09-08 15:18:21 CMasternodePayments::IsTransactionValid - Missing required payment - DQSq4brdBGpDitmdX8WCmGiwFQTDUPgGT3 240000000
2017-09-08 15:18:21 Invalid mn payment detected CTransaction(hash=36d0e78986, ver=2, vin.size=1, vout.size=2, nLockTime=0)
CTxIn(COutPoint(0000000000000000000000000000000000000000000000000000000000000000, 4294967295), coinbase 03019e00046a7ab2590881085eb313000000686578706f6f6c2e636f6d00, nSequence=0)
CTxOut(nValue=2.40000000, scriptPubKey=76a914c8657c6ea06829d23c5e1cdc)
CTxOut(nValue=9.60000000, scriptPubKey=76a9140e168310ca935ae8da40cd25)
That's because there is still someone that mines using the old wallet. Eventually your node get stuck and drops off the list.