When I chose "Window Capture (X composite)" mode on OBS, and select the running Windows 10 VirtualBox, I get a red screen:
It works fine with Spotify:
I can record the whole screen, but I'd like to be able to select the window so I can resize it and if I need to bring another window in front of it.
I'm using Ubuntu 14.04 with nVidia drivers - version 355.11. I will update to 364.15 if needed, but I'd rather not have to.