I have a private instance.
For the test machine, I installed the virtual box on a linux machine. Then created a Windows 8 VM in virtual box. The WPT agent is running well on this Windows 8 when I have a connection(VNC to the Linux server viewing the Windows 8 desktop). But when I close my VNC connection, let the test machine idle for a while(ex: 30 mins), run the WPT test again using this agent, the screenshot does not show the browser pages, it just shows the Window desktop (as attached image file).
But if I have the WPT test keeps running different tests(no idle or idle less than few mins between each test) on this agent even I close the VNC connection, the screenshot looks fine. Is there anything I need to adjust with in the test machine? Thanks,