Multiple base URLs
This means that the URL in question contains a base URL defined more than one.
Why is this important?
The base tag is used to determine the URL base for all relative links used within a page. A document can have no more than one base element, so multiple base tags is invalid, and this may cause problems for search engines crawling relative links.
What does the Hint check?
This Hint will trigger for any internal URL that contains at two or more base tags.
Examples that trigger this Hint:
Consider the URL: https://example.com/page-a
The Hint would trigger for this URL if it had more than one base tag, even if the base URL was the same:
How do you resolve this issue?
To resolve the immediate problem, simply remove superfluous base elements on any URLs that are affected. However, we also recommend that you should not use relative URLs at all (see further reading below).