This blog post prompted to look for ways to display a friendly error message to the user, explaining the issue and that upgrading the browser may help. This is what I found: https://stackoverflow.com/a/70671657

I would also like to display a friendly error message to the user if I resource fails to load because of a 404 or because of network issues. This is the only solution I found: https://stackoverflow.com/a/64243346/247696

Of course, I don't think this is the whole solution. But it's something we can do without waiting for browsers to get updated.