OK, so I think it's saying that you do indeed have a 2GB video card.
It may be that an X-Plane update, an increase in your monitor resolution or anti-aliasing settings, or something else caused X-Plane to start using a little bit more VRAM, and that didn't leave enough for SMP to work with. Laminar recommends 4GB or more for X-Plane 11.
Updating your video card would be money well spent, but failing that, there are some things you can try:
- Try lowering your monitor resolution, and disable any anti-aliasing your video driver may be set for.
- Assuming you can get to X-Plane's graphics settings, turn the quality down such that HDR is not enabled. Also disable any anti-aliasing for now.
- If at this point SMP will start up, disable any SMP features you don't need that consume more memory. Mainly, turn down the "cloud area" setting as far as you can tolerate, turn off cloud shadows, turn off cloud reflections, and set terrain blending to zero.
If that gets you up and running, you can start re-enabling the features most important to you until stability is impacted.