WordPress 6.4 update seems to be quite catastrophicWith most modern software, you could regard updating to any major version update to be "proper beta-testing."
Hence, I would advise against updating any production websites to major updates. Let the others do the beta testing. There are more than enough people who are happy to "always update ASAP."
Even with minor versions (patches and similar), such as 6.4.1 which I expect to see soon in order to fix some of the problems noticed in 6.4, it's usually a good idea to wait for a few weeks before updating (unless it's a critical security patch, in which case you can choose between risking with your website staying vulnerable, and risking a messy update messing up your site - your call ).
In terms of stability, it is most often better to wait for the first patch (at least).
Why wait with updates?In an ideal world, theme and plugin developers would test their plugin with the latest WordPress core's beta version, to confirm it all works. In the real world, that most often doesn't happen.
So even if the core itself is bug free (which doesn't really happen), one of your plugins or your theme could be causing problems, not working well with the lastest core version. It helps a lot if you use good quality plugins and theme(s), but it's still not guaranteed.
Testing in the staging environment definitely helps, but it is possible even for you, in your staging, to miss some problem that happens only in certain scenarios.
Hence, it is safer to wait a bit, let the others do all the "beta testing," and, ideally, update after the first patch is released.
The same goes for any plugin or theme updates, though that's usually a lot less critical (at least with high-quality ones).
I wrote on my website how you can edit the wp-config.php file to disable the automatic updates.
When you decide to update WordPress, it is usually best to:
- First update all the plugins (ideally one plugin at a time).
- Then update your theme(s).
- Finally update the WordPress core.
Update, November 9th, 2023:
Noted problems and the 6.4.1 patchWordPress patch version 6.4.1 was released, to fix some bugs.
These are most "prominent" bugs in 6.4 version:
- cURL error
"PHP Fatal error: Uncaught GuzzleHttp\Ring\Exception\RingException: cURL error 77"
This problem affected servers that used an older cURL library version cURL 7.29 (the current latest version is cURL 8.4.0). The bug prevented the WordPress install from downloading any further updates (for plugins, themes or WP core).
WordPress forum discussion on the 6.4 cURL bug
Link to a hotfix for those affected (I haven't tested it).
- Plugin backwards compatibility bug
wpdb::$use_mysqli property was removed because it was no longer needed by the WordPress core. However, it turned out that many plugins still use it (and tose plugins' developers apparently haven't updated their plugins to work with the WordPress 6.4).
WordPress forum discussion on the 6.4 backwards compatibility bug.