In brief. After I shut downed the server I've put dll file inside managed folder, then put both master and core file in plugins folder. Then when I start to boot up the server I was stuck on Success! So I checked the file as the picture i sent you. The Server won't boot up.
So I head back and removed all the plugins and only install the dll. I started up fine until i added the master.cs file and the core.cs file. The server console became crazye and spamming errors. I couldn't get what it said but i'll give you precise error in couple of days