Running masternode start via the debug console yields the following error:
Not capable masternode: can't detect external address. Please use the masternodeaddr configuration option. Nothing is mentioned in the initial post about having to do this, only using the default 127 / local loop address at least for a single master node.
It is not usually needed. I should just have s3v3n modify the instructions to include it, and, upon further review, I see that the start command is incorrect there, which is why you were entering it like that. I will let him know to fix that as well.
To use the masternodeaddr configuration option add masternodeaddr= in darknet.conf.