I create a new project. Run it and show a primary stage( a window in the OS Microsoft Windows 7).
I minimize this window a few minutes (less than one hours), the project is running well.
when I return back my home, the project is running, but when I restore the window the primary stage display all black and console output this follows message:
SwapChain allocation while the device is lost
RT Texture allocation while the device is lost
Create graphics while the device is lost
Create graphics while the device is lost
Create graphics while the device is lost
Create graphics while the device is lost
Create graphics while the device is lost
Create graphics while the device is lost
Create graphics while the device is lost


you could see the attachment, it's the screenshot of the issue reproduce.