I’m really sorry… The plugin did not compile normally.
I can’t help you efficiently… I make the “update” with many tries and I’m not a coder.
What I did is generate the SLN file, launch VS through it and tried to compile inside VS.
Doing this, I get more substantial error message and I manage to change what’s needed.
But I don’t get the second message you post here… I don’t know what upgradingNeo2 is nor why it doesn’t compile.
EDIT : When I look at my VS, I don’t have the UE4(VS 2015) thing you have… I have just UE4. Maybe it’s the root of your problem.