setFormFieldName() on a non-object magento Admin

Question

On manage product page, I'm getting no grid, I traced it and it shows the error

Fatal error: Call to a member function setFormFieldName() on a non-object in /app/code/core/Mage/Adminhtml/Block/Catalog/Product/Grid.php on line 279

I don't know whats wrong with it.

Answer 1

I think the FieldName value is invalid, it should be $this->getMassactionBlock()->setFormFieldName('product_id');