accessing media manager with different user persmissions

I built a plugin to store post image using media finder widget, and I set two roles admin and data-entry, when I'm accessing the backend with admin user I can add posts and images. But when I access the backend with data-entry user and when I click on media finder icon it generates the following error:

A widget with class name 'ocmediamanager' has not been bound to the controller" on line 513 of /modules/backend/Classes/Controller.php

I searched the net for any hint about this error but no luck.

I'm using October CMS Build: 434

Please advice,

via Chebli Mohamed