Magento : There has been an error processing your request

There has been an error processing your request  : Very common problem in magento when you’ll upgrade or import/export operation in magento .I faced this problem when i upgraded my magento

Invalid method Mage_Catalog_Block_Product_View_Description::addToParentGroup(Array
(
    [0] => detailed_info
)
)
Solution : The solution for this problem is go to your templates catalog.xml and comment out these lines