Warning: DOMXPath::query(): Invalid expression  in /home/httpstylati/public_html/vendor/manadev-shopgo/core/app/code/local/Mana/Core/Helper/Js.php on line 54

#0 [internal function]: mageCoreErrorHandler(2, 'DOMXPath::query...', '/home/httpstyla...', 54, Array)
#1 /home/httpstylati/public_html/vendor/manadev-shopgo/core/app/code/local/Mana/Core/Helper/Js.php(54): DOMXPath->query('')
#2 /home/httpstylati/public_html/vendor/manadev-shopgo/core/app/code/local/Mana/Core/Model/Observer.php(246): Mana_Core_Helper_Js->processFiles(Object(Mage_Catalog_CategoryController), Object(Shopgo_AdvIfconfig_Model_Magento_Core_Layout))
#3 /home/httpstylati/public_html/app/code/core/Mage/Core/Model/App.php(1358): Mana_Core_Model_Observer->processJsCssFiles(Object(Varien_Event_Observer))
#4 /home/httpstylati/public_html/app/code/core/Mage/Core/Model/App.php(1337): Mage_Core_Model_App->_callObserverMethod(Object(Mana_Core_Model_Observer), 'processJsCssFil...', Object(Varien_Event_Observer))
#5 /home/httpstylati/public_html/app/Mage.php(456): Mage_Core_Model_App->dispatchEvent('controller_acti...', Array)
#6 /home/httpstylati/public_html/app/code/core/Mage/Core/Controller/Varien/Action.php(339): Mage::dispatchEvent('controller_acti...', Array)
#7 /home/httpstylati/public_html/app/code/core/Mage/Catalog/controllers/CategoryController.php(148): Mage_Core_Controller_Varien_Action->generateLayoutBlocks()
#8 /home/httpstylati/public_html/app/code/core/Mage/Core/Controller/Varien/Action.php(418): Mage_Catalog_CategoryController->viewAction()
#9 /home/httpstylati/public_html/app/code/core/Mage/Core/Controller/Varien/Router/Standard.php(254): Mage_Core_Controller_Varien_Action->dispatch('view')
#10 /home/httpstylati/public_html/vendor/balke-technologies/magento-module-storemaintenance/app/code/community/BalkeTechnologies/StoreMaintenance/Controller/Router/Standard.php(90): Mage_Core_Controller_Varien_Router_Standard->match(Object(Mage_Core_Controller_Request_Http))
#11 /home/httpstylati/public_html/app/code/core/Mage/Core/Controller/Varien/Front.php(172): BalkeTechnologies_StoreMaintenance_Controller_Router_Standard->match(Object(Mage_Core_Controller_Request_Http))
#12 /home/httpstylati/public_html/app/code/core/Mage/Core/Model/App.php(365): Mage_Core_Controller_Varien_Front->dispatch()
#13 /home/httpstylati/public_html/app/Mage.php(692): Mage_Core_Model_App->run(Array)
#14 /home/httpstylati/public_html/index.php(94): Mage::run('', 'store')
#15 {main}