[aria-*] attributes do not have valid values
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. Native 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.)Each ARIA role supports a specific subset of aria-* attributes that define the state and properties of that role. For example, the aria-selected attribute indicates whether an element is currently selected depending on whether its value is true or false.If an element's ARIA attribute doesn't have a valid value, assistive technologies won't be able to interact with it as the developer intended.