Once on one of the sites auto-update of plugins was enabled, and after automatic Jetpack update, the site stopped working and an error was displayed:
There has been a critical error on your website. …
https://wordpress.org/support/article/faq-troubleshooting/
If you open the admin panel, then the error was also displayed.
The Jetpack developers made a bug in the code of the new version, which caused a very large number of WordPress sites to stop working after updating Jetpack, I deactivated Jetpack to make the site work and later on the same day the error was fixed by the developers, I updated Jetpack and activated it.
A similar problem can occur after updating any other plugin, to solve it, you can deactivate all plugins, then go to the admin panel and try to activate one plugin at a time until you find the problematic one.
You can view which active plugins in the database with an SQL query (you can do this before deactivating all plugins, for example, so that after solving the error, activate the plugins back with a SQL query):
SELECT * FROM `wp_options` WHERE `option_name` LIKE 'active_plugins';
The fastest way to deactivate all plugins is to rename the “plugins” directory to “plugins.hold”.
See my other articles about WordPress