About The Error
The 503 services unavailable error occurs when your web server is unable to get a proper response from a PHP script. This PHP script could be a WordPress plugin, a theme, or a misbehaving custom code snippet.
Fixing 503 Service Unavailable Error in WordPress
Step 1: Login to the control panel.
Step 2: Goto File Manager select domain and is there all WordPress core files available.
Step 3: Check the codes of .htaccess files.
Step 4: Rename the plugin folder and put DEBUG ‘true’ in the wp-config file so that we can find out the default plugin.
Step 5: If the plugin has been found uninstall the plugin from WordPress.
