Elements with an ARIA [role] that require children to contain a specific [role] are missing some or all of those required children
Webflow uses ARIA in some elements, such as TABS and the Hamburger menu. You don't need to do anything, it works fine.
If you get this error, check Custom Code or Element Settings > Custom Attributes.
Google Lighthouse says
Users of screen readers and other assistive technologies need information about the behavior and purpose of controls on your web page. Built-in HTML controls like buttons and radio groups come with that information built in. For custom controls you create, however, you must provide the information with ARIA roles and attributes. (Learn more in the Introduction to ARIA.)
Some ARIA roles require specific child roles. For example, the tablist role must own at least one element with the tab role. If the required child roles aren't present, assistive technologies may convey confusing information about your page, like announcing a tab set with no tabs.