Fix Fatal Error: Class Helper_Data Not Found – Magento Admin Panel

I have installed one module extension which throws an fatal error Fatal error: Class 'Mage_Clarion_Customerattribute_Helper_Data' not found in …/app/Mage.php on line 547 when i clicked on "Manage Attributes".

Following my \app\etc\modules\Clarion_Customerattribute.xml file

<config>
<modules>
    <Clarion_Customerattribute>
        <active>true</active>
        <codePool>community</codePool>
    </Clarion_Customerattribute>
</modules>
</config>

Following my \app\code\community\Clarion\Customerattribute\etc\config.xml file

<config>
<modules>
    <Clarion_Customerattribute>
        <version>0.1.0</version>
    </Clarion_Customerattribute>
</modules>

<global>
    <models>
        <clarion_customerattribute>
            <class>Clarion_Customerattribute_Model</class>
        </clarion_customerattribute>
    </models>
    <helpers>
        <clarion_customerattribute>
            <class>Clarion_Customerattribute_Helper</class>
        </clarion_customerattribute>  
    </helpers>
    <blocks>
        <clarion_customerattribute>
            <class>Clarion_Customerattribute_Block</class>
        </clarion_customerattribute>
    </blocks>
</global>

<frontend>
    <layout>
        <updates>
            <clarion_customerattribute>
                    <file>clarion_customerattribute.xml</file>
            </clarion_customerattribute>
        </updates>
    </layout>
</frontend>

<adminhtml>
    <layout>
        <updates>
            <clarion_customerattribute>
                <file>clarion_customerattribute.xml</file>
            </clarion_customerattribute>
        </updates>
    </layout>
</adminhtml>

<admin>
    <routers>
        <adminhtml>
            <args>
                <modules>
                    <clarion_customerattribute after="Mage_Adminhtml">Clarion_Customerattribute_Adminhtml</clarion_customerattribute>
                </modules>
            </args>
        </adminhtml>
    </routers>
</admin>
<!-- Clarion_Customerattribute_Adminhtml indicates the path of the admin controller-->
<default>
    <general>
        <validator_data>
            <input_types>
                <text>text</text>
                <textarea>textarea</textarea>
                <date>date</date>
                <boolean>boolean</boolean>
                <multiselect>multiselect</multiselect>
                <select>select</select>
            </input_types>
        </validator_data>
    </general>
</default>
</config>

Following my \app\code\community\Clarion\Customerattribute\etc\adminhtml.xml file

<config>
<menu>
    <customer>
        <children>
            <customer_attribute translate="title" module="clarion_customerattribute">
                <title>Manage Attributes</title>
                <sort_order>601</sort_order> 
                <action>adminhtml/customerattribute</action>
            </customer_attribute>
        </children>
    </customer>
</menu>
<!-- Aceess permission for the node admin/customer/customer_attribute-->
<acl>
    <resources>
        <all>
            <title>Allow Everything</title>
        </all>
        <admin>
            <children>
                <customer>
                    <children>
                        <customer_attribute translate="title" module="clarion_customerattribute">
                            <title>Manage Attributes</title>
                            <sort_order>601</sort_order> 
                                <children>
                                    <save translate="title">
                                        <title>Save Attribute</title>
                                        <sort_order>0</sort_order> 
                                    </save>
                                    <delete translate="title">
                                        <title>Delete Attribute</title>
                                        <sort_order>0</sort_order> 
                                    </delete>
                                </children>
                        </customer_attribute>
                    </children>
                </customer>
            </children>
        </admin>
    </resources>
</acl>
</config>

Here is \app\code\community\Clarion\Customerattribute\controllers\Adminhtml\CustomerattributeController.php

class Clarion_Customerattribute_Adminhtml_CustomerattributeController extends Mage_Adminhtml_Controller_Action
{
    protected function _initAction()
    {

         $this->_title($this->__('Customer'))->_title($this->__('Attributes'))->_title($this->__('Manage Attributes'));

         if($this->getRequest()->getParam('popup')) 
         {
            $this->loadLayout('popup');
         } 
         else 
         {
            $this->loadLayout()
        ->_setActiveMenu('customer/customer_attribure')
                ->_addBreadcrumb(Mage::helper('clarion_customerattribute')->__('Customer'), Mage::helper('clarion_customerattribute')->__('Customer'))
                ->_addBreadcrumb(
                    Mage::helper('clarion_customerattribute')->__('Manage Customer Attributes'),
                        Mage::helper('clarion_customerattribute')->__('Manage Customer Attributes'));
         }
         return $this;
          public function indexAction() 
          {
                $this->_initAction()->renderLayout();
          }
}

Here, \app\code\community\Clarion\Customerattribute\Helper\Data.php

class Clarion_Customerattribute_Helper_Data extends Mage_Core_Helper_Abstract
{   
//some code;
}

I tried to empty /var/cache folder. but it not work. I also tried to replace clarion_customerattribute to customerattribute in CustomerattributeController.php file but it not work.

Please help me for solving this problem (Fatal Error)