Thank you @Graziel his is actuall help message which i get when the cron is set automatic. but when i run the cron manually i did not get any error.
Welcome to CakePHP v3.2.12 Console
App : src
Path: /home/k12dev/public_html/src/
PHP : 5.6.30
Current Paths:
- app: src
- root: /home/k12dev/public_html
- core: /home/k12dev/public_html/vendor/cakephp/cakephp
Available Shells:
[DebugKit] benchmark, whitespace
[Migrations] migrations
[CORE] i18n, orm_cache, plugin, routes, server
[app] console, create_database, test, txp_payment
To run an app or core command, type cake shell_name [args]
To run a plugin command, type cake Plugin.shell_name [args]
To get help on a specific command, type cake shell_name --help
Content-type: text/html; charset=UTF-8

I think now you can understand the problem