Site crushes after WP 5.3.2 Upgrade

Try manually resetting your plugins (no Dashboard access required). If that resolves the issue, reactivate each one individually until you find the cause.

If that does not resolve the issue, access your server via SFTP or FTP, or a file manager in your hosting account’s control panel (consult your hosting provider’s documentation for specifics on these), navigate to /wp-content/themes/ and rename the directory of your currently active theme. This will force the default theme to activate and hopefully rule-out a theme-specific issue (theme functions can interfere like plugins).

Hi James, thanks for a replay.
I’ve lost most of my plugins (about 12) after upgrade. Yes, I’ve lost them literally. They disapear from plugins folder, gone, nothing. All activated, all turned on, all in use for years – jetpack for example. Fortunately I’ve got a ftp backup, so I copied and reactivated manually all of them. Now I’m trying to restore the site’s layout step by step.
But the point is – is it possible that the upgrade can erase plugins?
Does anyone have similar experiences?
Regards,
Greg

No, the upgrade does not touch plugin files, so I suspect something else may have caused it, possibly malware.

Carefully follow this guide. When you’re done, you may want to implement some (if not all) of the recommended security measures and start backing up your site.