Defualt Category product tab not work in cateogry page admin

Question

Fatal error: Call to a member function toHtml() on a non-object in app/code/core/Mage/Adminhtml/Block/Catalog/Category/Tabs.php on line 153

$this->addTab('products', array(
            'label'     => Mage::helper('catalog')->__('Category Products'),
            'content'   => $this->getLayout()->createBlock(
                'adminhtml/catalog_category_tab_product',
                'category.product.grid'
            )->toHtml(),
        ));

Answer 1

I think you have added some extension and that extension has created dropdown attribute for category.

for that dropdown attribute they have created some model method to fetch dropdown value but as you have disable that module magento won't find that source model for that attribute that's why you get this error.