So I recently made a server... It works out fine I suppose but I want to make it so that it's my Minecraft singleplayer world... This is hard to explain, but I found directions online that said I needed to delete the "world" file that came with the server, copy and paste my singleplayer world from the ".minecraft" "saves" file, and rename it "world". So I tried that.

I started up my server again but whenever I open the "minecraft_server.1.7.10" and have my friends join in, the console immediately closes and my friends get the error: "Internal Exception: java.io.IOExeption: An existing connection was forcibly closed by the remote host"

I've tried opening the "minecraft_server1.7.10" and waited, without my friends joining the server, and it just closes by itself after a couple seconds. It doesn't give me an error or crash report. It just closes.

So I deleted the whole thing and started anew with a new "minecraft_server.1.7.10" download (directly from minecraft.net). I opened the "minecraft_server.1.7.10" and started it up. It worked just fine. So I tried putting my singleplayer world in it. The same thing happened. It just, closed.

Another thing I noticed, when I opened the "world" file. The one from my singleplayer saves that I renamed "world". And I opened the one named "level". Nothing else, simply named "level" it says "E:Minecraft Server\world\level.dat" And underneath it says "Invalid value for registry". Thought that might help in a way...

Please help me! I am new to this Minecraft Server stuff, but any advice you have, please share with me!

(All of the "quotations" in this article are put to separate file names from the rest of the article, to avoid confusion. The "quotations" don't actually show up in the real file names or codes...)