The third pinned post at the top deals with those questions
https://ww.wp.xz.cn/support/topic/fatal-error-after-updating-to-the-most-recent-version-of-jetpack-read-this/
* We’ve made some changes to the Sitemaps feature in Jetpack 4.8, and inadvertently used code that isn’t compatible with old versions of PHP (PHP 5.3 or less).
* We’ll release a new update very soon to solve that problem.
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This reply was modified 9 years, 2 months ago by mantel.
