Magento 1.3 and Magento 1.4 Fix "call to member function toHtml()"

One of the errors you will usually encounter when you use a theme made for Magento 1.3 on Magento 1.4.1 0 version is that

"call to a member function toHtml()". There is a very easy fix for this error.

The Error comes like line number may differ

Fatal error: Call to a member function toHtml() on a non-object in                                                                      \app\code\core\Mage\Core\Model\Layout.php on line 529

just open the
 app\design\frontend\default\yourtheme\layout\page.xml

Find

<block type="core/profiler" output="toHtml"/>


Replace with

<block type="core/profiler" output="toHtml" name="core_profiler"/>

that's it the error will resolved just refresh the front end..Hope this will help you