the only thing I can think of now is about the browser you are using.
Are you using Chrome or Firefox? If not, could you try one of these browsers?
If you are using Chrome, try with Firefox. If with Firefox, try with Chrome.
If none of them worked, could you try updating them?
Please let us know your browsers versions before and after updating, because if it solves the problem, it could help other users.
If the problem is only in the simulation, then probably our browser doesn’t support WebGL.
Please try loading the page below to see whether WebGL is enabled in your browser: