**System Information**
Ubuntu, AMD Radeon.
**Blender Version**
Broken: 9b91e727be3b (blender2.8 HEAD)
Worked: 2.79a, and early 2.8 too
**Short description of error**
Crash when using sequencer preview.
**Exact steps for others to reproduce the error**
* Create a new scene
* Change editor to VSE
* Add a scene strip
* Change sequencer draw mode to Sequencer/Preview
Or open this 2.79 file:
{F3759676}
`BLI_assert failed: //source/blender/windowmanager/intern/wm_window.c:2312, WM_opengl_context_activate(), at 'GPU_framebuffer_current_get() == 0'`
**Full backtrace:** P734