User's are Disappearing or being Deleted Automatically

From time-to-time we get reports that User's have been unknowingly deleted or removed from the site.

Below is the list of known reasons for this to occur. There's probably more, but these are the one's we know about so far.

1. Site owner, Developer, or Web-host restores website database from old backup (causing new data to be lost). There's not much you can do to avoid this, except perhaps take more frequent backups, or use a service like VaultPress where you can selectively choose which data to restore.
2. Site owner, Developer, or Web-host has pushed a staging database to live site. Causing some staging site data to overwrite live data.
3. Site owner or Web-host has Database/Object caching enabled, causing some accounts to get overridden by POST data from a new signup (Most common on WP Engine or GoDaddy). This is extremely difficult to reproduce, but disabling the database/object caching fixes it.
   1. To resolve this with WP Engine, turn off their Object Caching in your control panel settings for your site, or contact their support and ask for object caching to be disabled.
   2. As for GoDaddy Managed hosting, this cannot be turned off. We recommend moving to a new host as GoDaddy's support is unwilling to assist with any caching issues. GoDaddy can move you to their Shared or Business hosting plans which do not have the same caching forced. But after the migration, they sometimes forget to delete the caching scripts, so be sure they remove their caching scripts after migrating you...otherwise you'll end up with the same problem.
4. Another Admin on the site has deleted the account accidentally and didn't tell you.
5. BuddyPress/BuddyBoss option to allow users to delete their own accounts is enabled. Turn this setting off to stop this.
6. WooCommerce Personal data retention is not set to indefinite. Set this to indefinite to stop this from happening.