'Invalid Form Key. ' when trying to save editing product from admin

[jfan2006]

I google and only find it's to do with 

<input name="form_key" type="hidden" value="<?php echo Mage::getSingleton('core/session')->getFormKey() ?>" />

and I have tried a couple of solutions but still can't get the one which works for me...

Magento Community Edition V1.7.0.2

Any idea/suggestion? 

Thanks! 

[theMageComp]

@jfan2006

Do you have any custom extension which has a field which affects Admin product page? If so disable it and try again.

[KuafuSoft]

first thing first, open product editing page and view source, find if there is

<input name="form_key" type="hidden" value=".....

[jfan2006]

No, it deosn't have any cases in  \app\design\adminhtml\default\default\template\catalog\product   directory files.

[KuafuSoft]

I mean check the html code in browser in source view.

in template, its added like this

<?php echo $this->getBlockHtml('formkey')?>

we need to first make sure its there in the html, then figure out why its not sent to server or why the value is incorrect.

[jfan2006]

 Yes, in the source code, it does have 

<input name="form_key" type="hidden" value="......." />

and I belive it comes from this code: 

app/design/adminhtml/default/template/formkey.phtml

<div><input name="form_key" type="hidden" value="<?php echo Mage::getSingleton('core/session')->getFormKey() ?>" /></div>

which seems correct.

[KuafuSoft]

in Mage_Core_Controller_Varien_Action::_validateFormKey

var_dump($this->getRequest()->getParam('form_key', null), Mage::getSingleton('core/session')->getFormKey());

if they contain different hash value, then your core/ession is not holding generated form key,

if the first is empty, then your form key is not sent back,

if the first is some non-hash string, then your form key is overided by some other filed.

[jfan2006]

Yes, indeed. The first value

$this->getRequest()->getParam('form_key')

 is NULL.  

[KuafuSoft]

make sure its in the form element, or there isn't another form_key field with empty value

[jfan2006]

Do you mean, i should replace all

$this->getRequest()->getParam('form_key')

on the site with

Mage::getSingleton('core/session')->getFormKey()

?