I have try to install stamped.io extension, after install back-end showing following error if i click stamped.io setting.

Fatal error: Uncaught Error: Class 'Stamped_Core_Block_Adminhtml_System_Config_Form_Button' not found in /home/abc/public_html/app/code/core/Mage/Core/Model/Layout.php:590 Stack trace: #0 /home/abc/public_html/app/Mage.php(533): Mage_Core_Model_Layout->getBlockSingleton('\n ...') #1 /home/abc/public_html/app/code/core/Mage/Adminhtml/Block/System/Config/Form.php(310): Mage::getBlockSingleton('\n ...') #2 /home/abc/public_html/app/code/core/Mage/Adminhtml/Block/System/Config/Form.php(229): Mage_Adminhtml_Block_System_Config_Form->initFields(Object(Varien_Data_Form_Element_Fieldset), Object(Mage_Core_Model_Config_Element), Object(Mage_Core_Model_Config_Element)) #3 /home/abc/public_html/app/code/core/Mage/Adminhtml/Block/System/Config/Form.php(164): Mage_Adminhtml_Block_System_Config_Form->_initGroup(Object(Varien_Data_Form), Object(Mage_Core_Model_Config_Element), Object(Mage_Core_Model_Config_Element)) #4 /home/abc/public_html/app/code/core/Mage/Adminhtml/Block/System/Confi in /home/abc/public_html/app/code/core/Mage/Core/Model/Layout.php on line 590


class Stamped_Core_Block_Adminhtml_System_Config_Form_Button extends Mage_Adminhtml_Block_System_Config_Form_Field
     * template
    protected function _construct()

     * return html
     * @param  Varien_Data_Form_Element_Abstract $element
     * @return string
    protected function _getElementHtml(Varien_Data_Form_Element_Abstract $element)
        return $this->_toHtml();

How to solve the class missing error?

  • can you please update your code where you have use the Form/Button.php Nov 1, 2019 at 7:06
  • @RakeshVarma Pls check with my updated post.
    – zus
    Nov 1, 2019 at 7:20

1 Answer 1


At first sight, I could identify that:


path should be:


Notice the typo in AdminHtml, which should be Adminhtml.

Please fix this and let me know if you find any other problem further.

  • Great, how to find this kind of error? Recommend any editor or something else?
    – zus
    Nov 1, 2019 at 7:52
  • There is no magical editor trick. Just follow the core principles of Magento for naming conventions. Nov 1, 2019 at 8:01
  • I have magento in localhost, here app/code/community/Stamped/Core/Block/AdminHtml/System/Config/Form/Button.php working, may i know the difference?
    – zus
    Nov 1, 2019 at 9:00
  • 1
    Maybe you are using the Windows system for the localhost. There is a major difference between a Windows and a Linux system. The folder names AdminHtml, adminhtml, and Adminhtml are same for Windows, but these are threee different folders for Linux. Nov 1, 2019 at 9:28
  • Yes, I am using Windows for testing and development. Thank you for your explanation.
    – zus
    Nov 1, 2019 at 9:29

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