stop unity pausing when it loses focus

This solution from burnumd, worked for me. You can change the setting via the menu rather than through code...

"In the editor, go to Edit -> Project Settings -> Player. The inspector pane will now change to show the player settings. Look for the option that says "Run In Background" and check it."

http://answers.unity3d.com/questions/9899/how-do-you-keep-your-game-running-even-when-you-sw.html

Doing some necromancy here, but just to add, you still can't move around or interact with the Unity application if it loses focus. It will still run, but you will be unable to do anything.

Anybody got a solution?

@David 3

(on Win) If you have several tasks on the taskbar (bottom), try clicking on the Unity task and again and again until the next window appears over the unity window. The Unity process should still running.