Unable to log in to Magento Backend

[jriceart]

While trying to log in to a clients Magento store, I receive the following errors and I am unsure of how to proceed. Any help would be greatly appreciated.

Mage registry key "_singleton/Mage_Core_Model_Domainpolicy" already exists

Trace:
#0 /home/pproduct/public_html/app/Mage.php(223): Mage::throwException('Mage registry k...')
#1 /home/pproduct/public_html/app/Mage.php(477): Mage::register('_singleton/Mage...', false)
#2 /home/pproduct/public_html/app/code/core/Mage/Core/Model/App.php(1317): Mage::getSingleton('Mage_Core_Model...')
#3 /home/pproduct/public_html/app/Mage.php(448): Mage_Core_Model_App->dispatchEvent('controller_acti...', Array)
#4 /home/pproduct/public_html/app/code/core/Mage/Core/Controller/Varien/Action.php(527): Mage::dispatchEvent('controller_acti...', Array)
#5 /home/pproduct/public_html/app/code/core/Mage/Adminhtml/Controller/Action.php(160): Mage_Core_Controller_Varien_Action->preDispatch()
#6 /home/pproduct/public_html/app/code/core/Mage/Core/Controller/Varien/Action.php(407): Mage_Adminhtml_Controller_Action->preDispatch()
#7 /home/pproduct/public_html/app/code/core/Mage/Core/Controller/Varien/Router/Standard.php(254): Mage_Core_Controller_Varien_Action->dispatch('login')
#8 /home/pproduct/public_html/app/code/core/Mage/Core/Controller/Varien/Front.php(172): Mage_Core_Controller_Varien_Router_Standard->match(Object(Mage_Core_Controller_Request_Http))
#9 /home/pproduct/public_html/app/code/core/Mage/Core/Model/App.php(354): Mage_Core_Controller_Varien_Front->dispatch()
#10 /home/pproduct/public_html/app/Mage.php(684): Mage_Core_Model_App->run(Array)
#11 /home/pproduct/public_html/index.php(87): Mage::run('', 'store')
#12 {main}

[Damian Culotta]

Hi @jriceart,

Can you start testing by disabling 3rd-party modules? Also, can you test using a default theme (rwd/default)?

The Domainpolicy is a core model and Magento works fine so I guess you have a module or something within your theme that creates the conflict.

[Damian Culotta]

Which version of Magento are you using?

[jriceart]

Hi Damian,

Sorry for the delayed reply, I was trying to get in contact with the original developer of the website, to see if they had developed updated modules that are compatible with the security patches but, it's looking unlikely.

I disabled the third party modules and we are still receiving the same error codes, my next step is to disable the theme. The site is running 1.9.1.0

[Damian Culotta]

To be honest, at this point, I'm out of ideas.

Maybe you'll need to ask for qualified support to check the problem (getting access to the code/environment).

[jriceart]

Thank you Damian, I appreciate you taking a look. I just feel really bad for the client at this point, sounds like they were horrendously overcharged to build the site originally by a contractor who just outsourced the whole build to other contractors and then the guy just refuses to support his work.