Softaculous extension does not open: Call to a member function dispatch() on null

Symptoms

• The Softaculous tool within Plesk displays the following error once opened:
  

  PLESK_INFO: 500 Error
  Message Call to a member function dispatch() on null
  
  Type Error
  Message Call to a member function dispatch() on null
  File index.phtml
  Line 1

• The following error can be found in the in the /var/log/plesk/panel.log of your server:
  

  CONFIG_TEXT: [2023-03-23 03:44:39.714] 3036096:641b68b7ae657 ERR [panel] Call to a member function dispatch() on null:
  0: /usr/local/psa/admin/plib/modules/softaculous/views/scripts/index/index.phtml:1
  include()
  1: /usr/local/psa/admin/plib/vendor/plesk/zf1/library/Zend/View.php:157
  Zend_View->_run(string '/usr/local/psa/admin/plib/modules/softaculous/views/scripts/index/index.phtml')
  2: /usr/local/psa/admin/plib/vendor/plesk/zf1/library/Zend/View/Abstract.php:888
  Zend_View_Abstract->render(NULL null)
  3: /usr/local/psa/admin/plib/Application/Controller/Action/Helper/ViewRenderer.php:22
  Plesk\Application\Controller\Action\Helper\ViewRenderer->render()
  4: /usr/local/psa/admin/plib/vendor/plesk/zf1/library/Zend/Controller/Action/Helper/ViewRenderer.php:972
  Zend_Controller_Action_Helper_ViewRenderer->postDispatch()
  5: /usr/local/psa/admin/plib/vendor/plesk/zf1/library/Zend/Controller/Action/HelperBroker.php:277
  Zend_Controller_Action_HelperBroker->notifyPostDispatch()
  6: /usr/local/psa/admin/plib/vendor/plesk/zf1/library/Zend/Controller/Action.php:527
  Zend_Controller_Action->dispatch(string 'indexAction')
  7: /usr/local/psa/admin/plib/vendor/plesk/zf1/library/Zend/Controller/Dispatcher/Standard.php:308
  Zend_Controller_Dispatcher_Standard->dispatch(object of type Zend_Controller_Request_Http, object of type Zend_Controller_Response_Http)
  8: /usr/local/psa/admin/plib/vendor/plesk/zf1/library/Zend/Controller/Front.php:954
  Zend_Controller_Front->dispatch()
  9: /usr/local/psa/admin/plib/pm/Application.php:87
  pm_Application->run()
  10: /usr/local/psa/admin/htdocs/modules/softaculous/index.php:11

• Latest version of the Softaculous extension for Plesk is already installed

Cause

ionCube loader is missing for all PHP versions installed on the server.

Resolution

Install ionCube loader for any PHP version by following instructions from the article How to enable ionCube Loader module for PHP shipped with Plesk on Linux?