xampp - PHP artisan return Undefined index: HTTP_USER_AGENT -

i tried run php artisan in project folder using command prompt. however, error keeps popping up:

  [errorexception]    undefined index: http_user_agent 

running same command in other projects' folder (with laravel 4.2 , 5.1) worked fine.

from i've read on laracast: service providers need commented out. however, in particular project don't have any.

you should verify controllers constructors or artisan command constructors. might launched when running php artisan , if in of them using directly http_user_agent or launching piece of code requires http_user_agent makes problem.