Fix the “Copy site failed” error in WP Engine

Try the following fixes:

1. Confirm that wp-config.php doesn’t have the WP_HOME or WP_SITEURL constants defined. Remove them if found (on both origin and target environments).
2. In the target environment, open phpMyAdmin and confirm that the values of siteurl and home in the wp_options table is set to the target URL and not the origin URL.

Origin: the environment that you are copying.

Target: the environment to where you are copying.