Blender 2.77 cycles. Smoke generation stops working when I click on flow I'm trying to get fire/smoke working in Blender. I have Blender 2.77 running on Windows 7. To reproduce:  


Create a new file (Ctrl+N)
switch to Cycles Render
Select the cube
Choose Object > Quick effects > Quick Smoke in 3D View header.
Press Alt+A to play animation. Smoke appears as expected
Go to the Physics tab on the newly created smoke object. Click on "Flow".


Smoke disappears and doesn't appear again when the animation is played again.
For smoke to work you need at least two things:

A Smoke Flow Object, the source where the smoke is generated from.

A Smoke Domain that contains the smoke simulation.

When you select an object and apply Quick smoke, a new object appears. That "newly created object" is the smoke domain.

If you convert the smoke domain to flow, the smoke simulation will not work. To change the flow settings select the original object.