Unable to open Magento Admin page

Question

I installed following extension.

http://www.magentocommerce.com/magento-connect/kancart-mobile-web-mobile-app-108-themes-in-1-freemium-mobile-web-mobile-app-service.html

But I came to not enter dashboard page.(Admin page can not be opened) It shows following error:

There has been an error processing your request Exception printing is disabled by default for security reasons.

Error log record number: 731249982844.

So I checked report directory.

a:5:{i:0;s:75:"Mage registry key "_singleton/Kancart_MobileApi_Helper_Data" already exists";i:1;s:1533:"#0

I appreciate anyone help Thank you.

Answer 1

This method helped me to fix this problem. I am not sure, whether it is a correct way or not.. But give a try.

Only admin page will not load. But your website will load.. Add /downloader to the base url in the browser. You will be directed to Magento Connect Manager. Login and unistall the extension. And logout. Remove the maintenance.flag file in the magento main folder. Now try to log in into the admin panel.

Answer 2

try to disable Kancart_MobileApi module and check it.

if works then check module config.xml and find out any observer and find out singleton, replace with model