Step 4 in the single masternode setup has an error in it. Where it says should also include the port. This took me a few hours to figure out and kept giving me the 0 port error.
Here is my darknet.conf
addnode=108.61.151.69
addnode=173.245.158.8
addnode=coin-server.com
addnode=185.117.72.180
addnode=164.132.25.216
addnode=5.39.8.251
addnode=164.132.143.9
addnode=46.8.44.81
addnode=104.172.24.79
addnode=2.230.243.216
listen=1
server=1
daemon=1
port=51472
logtimestamps=1
maxconnections=256
rpcuser=s0methingCrazyAndRandom
rpcpassword=s0methingCrazyAndRandom
rpcport=51470
rpcallowip=127.0.0.1
masternodeaddr=:51472
masternode=1
masternodeprivkey=XXXXXXXXXXXXXXXXyourMasternodePrivkeyXXXXXXXXXXXXXXXXXXXXX
I also added to the file for masternodes.conf (not sure if this was necessary for a single node):
# Masternode config file
# Format: alias IP:port masternodeprivkey collateral_output_txid collateral_output_index
# Example: mn1 127.0.0.2:51474 93HaYBVUCYjEMeeH1Y4sBGLALQZE1Yc1K64xiqgX37tGBDQL8Xg
MasterNode 127.0.0.1:51472 masternodeprivkey collateral_output_txid collateral_output_index