Content source %1 has at least one item in crawl database %2 that has consistently failed over several consecutive incremental ...

Content source %1 has at least one item in crawl database %2 that has consistently failed over several consecutive incremental crawls. Because of this, the search system will do a full crawl of %3 URLs in one of the next incremental crawls. To see which item(s) failed, view the crawl log and filter to top level errors for the content source%4.