Nothing displays at all.
WHAT IT MEANS
PHP stopped and errors are not being displayed, which is correct for a live site and unhelpful for diagnosis.
THE FIRST STEP
Enable error logging and reproduce.
In WordPress, add to wp-config.php:
define('WP_DEBUG', true);
define('WP_DEBUG_LOG', true);
define('WP_DEBUG_DISPLAY', false);Then read wp-content/debug.log.
Or check cPanel > Metrics > Errors, which frequently has the entry already.
THE COMMON CAUSES
A PHP fatal error in a plugin or theme Memory exhausted A syntax error in a recently edited file An incompatible PHP version
ISOLATING IT WITHOUT THE LOG
Rename the plugins directory in File Manager. If the site returns, a plugin is responsible.
Rename it back and disable plugins individually to find which.
Switch to a default theme to rule out theme code.
MEMORY
Raise memory_limit in cPanel > MultiPHP INI Editor and retest. If that resolves it, something is consuming more than it should.
AFTER AN EDIT
Suspect the edit. Restore your backup copy of the file.
