Downgrading wp from 6.4.3 to 5.2.2

Hi @ramzan32,

-Backups: Before downgrading, it’s crucial to have a backup of your site. If you have a backup taken before the upgrade to version 6.4.3, restore it to revert your WordPress installation.
-Verify the PHP version: Make sure WordPress 5.2.2 and your PHP version are compatible. PHP versions 5.6.20 to 7.3 are supported by WordPress 5.2.2, so make sure your version is compatible.
-Update PHP Version: You should think about updating your PHP version to one that is within the supported range if it is less than 5.6.20. By contacting your hosting company or using your hosting control panel, you can update the version of PHP you’re using.
-Verify that the themes and plugins you have installed are compatible with WordPress 5.2.2 by reviewing compatibility. Errors may occur if older themes and plugins are incompatible with the reduced version.
-Edit script-loader.php by hand: You might need to manually edit the script-loader.php file if the error persists after the downgrade. Navigate to line 757 of the file C:\xampp\htdocs\www\wordpress\wp-includes\script-loader.php. If you see any curly braces being used for offset access to strings or arrays, make sure they are replaced with a PHP 5.2.2 compatible syntax.
-Look About Plugin Conflicts.
-Update Themes and All Plugins.

Hope this helps you.

Unless you have a backup that you can restore from, downgrading is a dangerous process, which is why backing up before upgrading is strongly recommended both in the upgrade instructions and automatic upgrade interface.

Did the error occur after the downgrade, or are you downgrading because of it?

If you’re downgrading because of it, instead of downgrading, 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. Hopefully, this will force the default theme to activate and rule out a theme-specific issue (theme functions can interfere like plugins).