These are the current nodes in blockchain nodelist that's why you are now not able to connect.
This nodelist forks/goes offline frequently so depending on those ips are not safe.
Another thing is that, the greencoin.crypto-expert.com is not accessible for me most of the time.
So inshort this issue need to be address asap.
addnode=101.182.168.159
addnode=111.92.47.27
addnode=212.243.7.37
addnode=37.187.88.140
addnode=45.55.250.196
addnode=50.159.71.79
addnode=50.205.123.50
addnode=50.34.139.183
addnode=59.97.46.149
addnode=67.161.120.48
So are these the ones I should now drop into my config file?  Why do these IPs keep changing and how do we know what should be current in config file?
Jim, when there is staking turmoil some of the nodes change if some bad players come. We haven't really confirmed if this is the case or not, but worth pointing out. I mentioned above in the thread that "connect" will dump all of your "addnode"'s in favor of the one connection, so if Ahmed is working on the coin and takes his node down then maybe all of your other addnode's aren't helping you.
I have a client running right now and here are the peers:
"addr" : "37.187.88.140:11517",
"addr" : "149.202.137.169:11517",
"addr" : "212.243.7.37:11517",
"addr" : "45.55.250.196:11517",
"addr" : "50.34.139.183:11517",
"addr" : "67.161.120.48:11517",
and from the block explorer:
addnode=111.92.47.27
addnode=212.243.7.37
addnode=37.187.88.140
addnode=45.55.250.196
addnode=50.159.71.79
addnode=50.205.123.50
addnode=50.34.139.183
addnode=67.161.120.48
As far as getting 1 node off and on, there's a protocol written into the software to try and ban "bad players", e.g. if the protocol is sensing an attempt to 51% attack it can ban the node for awhile. I've found if you wait 24 hours and try downloading the blockchain from scratch with  a fresh list of addnodes in the conf file that you get it to sync. Sometimes it stops during the download, and you simply close and re-open to restart the chain downloading. This has been working for me lately.