My systemd hangs on "systemd start service_name"

I'm trying to run a Minecraft server like this

[Unit]



Description = Run Paperclip server
Next = network.target

[Service]
Type = forking
ProtectHome = true
ProtectSystem = complete
PrivateDevices = true
PrivateTmp = true
NoNewPrivileges = true

InaccessibleDirectories = / root / sys / srv / media - / lost + found
ReadWriteDirectories = / opt / minecraft
WorkingDirectory = / opt / minecraft
User = Minecraft
Group = Minecraft

ExecStart = / usr / bin / screen -DmS minecraft / usr / bin / java -Xmx1536M -jar paperclip.jar
ExecStop = / usr / bin / screen -p 0 -S minecraft -X & # 39; save everything & # 39;
ExecStop = / usr / bin / screen -p 0 -S minecraft -X & # 39; stop & # 39;
ExecStop = / bin / sleep 5

[Install]
WantedBy = multi-user.target

It works except that the systemd will not "come out". It just hangs in the terminal. I can press ctrl-D or eventually, but this is not a desired behavior. What am I missing?