Has conflicting incoming hreflang annotations
This means that the URL in question has multiple, different incoming hreflang annotations.
Why is this important?
Hreflang tags are interpreted by search engines as indexing instructions. An English page that has hreflang pointing at its French alternate is instructing search engines to index both the English version and the French version, and to consider each as equivalent in their respective languages.
In this situation, we describe the French page as having incoming hreflang from the English page. If there was another page, say the German page, which had hreflang pointing at the French page, but referencing it as the Spanish page, this would case a conflict.
How would search engines know if the page should be considered as the French alternate, or the Spanish one?
This sort of conflicting signal will cause search engines to ignore the hreflang instruction.
What does the Hint check?
This Hint will trigger for any URL which has incoming hreflang annotations from multiple different URLs, where the annotations do not match.
Note: This Hint is very similar to another Hint: Has conflicting outgoing hreflang annotations. The difference being that this Hint is analysing the target page of a hreflang annotation (i.e. incoming hreflang) whereas the other Hint is analysing the page with hreflang on (i.e. outgoing hreflang).
Examples that trigger this Hint:
Consider the URL: https://example.com/fr/page-a/
The Hint would trigger for this URL if it had incoming hreflang from one page;
and if it also had incoming hreflang from another page, that is different to the above;
How do you resolve this issue?
The problem with this sort of conflicting instruction is that it is not obvious to search engines which page is causing the error. Hopefully, it is easier to figure out as a human (with some knowledge or awareness of foreign languages!).
You will need to inspect the hreflang to identify the incorrect pattern, then either manually update the URLs to correct the mistake, or fix the script that generates the hreflang (depending on how the site is setup).
Ultimately, you need to end up in a situation where there is consistency across all hreflang annotations - so that every page references the French page, as the French page.