Why is Normal Builder greyed out with an Upgrade tag when I edit a page?

The Normal Builder (the full-screen visual section editor) depends on your plan. When it isn't included, the Normal Builder choice under Editor type is greyed out with an Upgrade tag, and only Content editor can be selected.

You can still:

• Write the page in the Content editor, with text, images and formatting, and click Save changes.
• Click Upgrade, which opens Account → Subscription, to see which plans include the builder.

Once your plan includes it, choose Normal Builder and click Open Builder →. Text written in the Content editor isn't lost when you switch.