Hi,
Sorry for the trouble. First please enable the wp_debug so you could get a clear idea about the issue. You may add those codes on your wp_config.php file then you should get the exact error code on the WordPress dashboard or frontend of the site.
// Enable WP_DEBUG mode
define( 'WP_DEBUG', true );
// Enable Debug logging to the /wp-content/debug.log file
define( 'WP_DEBUG_LOG', true );
// Disable display of errors and warnings
define( 'WP_DEBUG_DISPLAY', false );
@ini_set( 'display_errors', 0 );
// Use dev versions of core JS and CSS files (only needed if you are modifying these core files)
define( 'SCRIPT_DEBUG', true );
Then share the error code here so I or someone could help you. ??