Following errors are listed in the errors view section:

• Callback
  • After 10th attempt with still no HTTP 2xx response it will be listed as "warning" in errors view (assuming default value "10" is configured in _global.xml for "notificationErrorThreshold")
  • After 30th attempt with still no HTTP 2xx response it will be listed as "error" in errors view & permanent give-up (assuming default value "30" configured in _global.xml for "notificationMaximumRetries")
    • Can be triggered again from the errors view

For detailed information about callbacks please see: API Documentation#Callbacks

For more information about _global.xml please see: GlobalXML (restricted access)