I have a Virtual Private Server (VPS) through Digital Ocean, and I'm using PuTTY to SSH to it. I have a Minecraft server, and whenever I launch the server, it creates a `screen` session.

Whenever I press `Ctrl`+`A` `D` or any other combination of `A` and `D`, nothing happens. I've tried `Ctrl`+`Alt`+`D`, `Ctrl`+`A` `Ctrl`+`D`, `screen -D`, and nothing seems to work.

`Ctrl`+`A` `D` only seems to work once every few dozen times I completely restart the server.

`Ctrl`+`C` works fine, but it also shuts off the Minecraft server. If I close PuTTY, it also closes the server. Is there any other way I can detach the screen, or have Minecraft auto-launch when the VPS starts up?

It's running on Ubuntu 16.04 64-bit.