Incorrect response received. Stopped!Rebuilding Htpasswd Db...

Hi, i´m just upgraded from my v3 to v4, but when i try to access to my protected folders, it shows a 404 error page, i try to rebuild my htpasswd database, but it says that:

Incorrect response received. Stopped!Rebuilding Htpasswd Db...

In my log, it shows this:

Code:

Exception Am_Exception_InternalError
Am_Protect_Htpasswd->onRebuild
call_user_func [ application/default/controllers/AdminRebuildController.php : 232 ]
AdminRebuildController->doAction [ library/Am/Controller.php : 139 ]
Am_Controller->_runAction [ library/Am/Controller.php : 116 ]
Am_Controller->dispatch [ library/Zend/Controller/Dispatcher/Standard.php : 295 ]
Zend_Controller_Dispatcher_Standard->dispatch [ library/Zend/Controller/Front.php : 954 ]
Zend_Controller_Front->dispatch [ library/Am/App.php : 1916 ]
Am_App->run [ index.php : 43 ]

I tried to change permissions on my .htpasswd file, finally tried with 777, but it still failing...

I need to arrange it quickly, my users can´t access to the protected urls...

Thank you