I see “Could not find asset snippets/...liquid”. How do you fix it?

That error, e.g. Liquid error (sections/main-product line 42): Could not find asset snippets/price.liquid, means a {% render %} or {% include %} points at a snippet file that was renamed, deleted, or never uploaded. We either restore the missing snippet or repoint the include to the correct file name, then check the rest of the theme for other references to the same asset.