Duplicate meta description
What it means
Several indexable pages share the same meta description. A snippet that describes a whole section rather than the page tends to be discarded and rewritten.
How to fix it
Rewrite each one around what that page specifically offers. As with titles, templates are the usual cause; if writing one per page is impractical for thousands of pages, build the description from the page's own fields rather than repeating a constant.
Finding it in CrawlStat
After a crawl, open Issues and pick Duplicate meta description. Click Show all in Pages to filter the Pages table to the affected pages, or Export affected to hand the list to whoever owns the fix. Audit ID: description_duplicate.