Codeigniter + HMVC is only requesting login_lang file ... all other module's lang files are not being loaded
In the language you put the module name first. You can create a language folder inside the module lets say modules => admin => language => en
modules => admin => language => en => dashboard_lang.php
$autoload['language'] = array('admin/dashboard');
Or On Controller
modules => admin => language => en => dashboard_lang.php
$this->lang->load('admin/dashboard', 'english');
With Sub Folder
modules => admin => language => en => common => dashboard_lang.php
$autoload['language'] = array('admin/common/dashboard');
Or On Controller
modules => admin => language => en => common => dashboard_lang.php
$this->lang->load('admin/common/dashboard', 'english');