Did it ever work? Shotcut is not compatible with all systems. That is why system requirements in the FAQ states “OpenGL 2.0 that works correctly and is compatible.” From your log
[Warning] <> QQuickWidget::resizeEvent() no OpenGL context
So, OpenGL is the problem. However, Shotcut defaults to trying to use an OpenGL to DirectX converter, and I see that in your log as well:
[Info ] Mlt::GLWidget::initializeGL OpenGL renderer “ANGLE (Microsoft Basic Render Driver Direct3D11 vs_5_0 ps_5_0)”
For whatever reason, these are not working, and I can only refer you to a registry setting to change the startup Display Method: