emply

Facebook say: “List Item is Empty: Either remove empty list item or add content to it.
No Valid List Items Found: Lists should have at least one item. Please make sure that at least one < li> exists within a list element. Refer to List under Format Reference in the Instant Articles documentation for more information.
List Contains Unsupported Elements: Each list may only contain a single text-related element. See prior errors for more details.”

but if there is contained within

• on the web, but the plugin not exported to instant.

https://wordpress.org/plugins/fb-instant-articles/