Seemingly Random Unity lock-ups (not responding) with 0% CPU Usage

I'm on Windows 10 with Unity 5.4.1f1, but this issue has been around for at least one previous revision of Unity.

I occasionally have Unity lock-up (stops responding) on me for no reason that I can identify. I believe it has happened in other circumstances, but most often it seems to happen after hitting the play button after Unity has been sitting idle in the background for a long time.

When this happens the Unity Editor will become completely unresponsive and the only solution is to forcibly end the task.

I check the task manager and the RAM seems nominal and non-increasing, and the CPU sits at 0% usage. I've experienced lock-ups due to bad code before, typically infinite or stupidly long loop that leads to increasing RAM and constant CPU usage. This doesn't seem to be the case here, especially given the fact that it has persisted across multiple updates to Unity and my code, in addition to the fact that the game runs perfectly almost every time.

Has anyone else experienced this, or does anyone have any idea where to investigate?