Issue loading infinity when i activate plugin on PHP 7

Hello @huynhhuynh

This will need a little more of investigation, as PHP v.7 shouldn’t cause that.

Could you please update PHP to v.7 again, then access your server via FTP, edit wp-config.php file, find a line like
define('WP_DEBUG', false);and replace it with the following (if the above line doesn’t exist, simply insert next snippet just above the /* That’s all, stop editing! Happy blogging. */ comment)

// Enable WP_DEBUG mode
define('WP_DEBUG', true);
// Enable Debug logging to the /wp-content/debug.log file
define('WP_DEBUG_LOG', true);
@ini_set( 'log_errors', 1 );
// Disable display of errors and warnings
define('WP_DEBUG_DISPLAY', false);
@ini_set('display_errors', 0);

Then go ahead and try to replicate the error, by activating our plugin again and the infinite load comes up again.
By doing so, a /wp-content/debug.log file should be created. Simply download it and use a service like Dropbox or Google Drive to upload it and post the shareable link here in your next reply. 🙂

Ref: https://premium.wpmudev.org/blog/debugging-wordpress-how-to-use-wp_debug/

Warm regards,
Dimitris