Error message "Mage registry key already exists" after extension installation
Last update: 21.10.2020 -
Christoph Maßmann
After installing a Magento 1 extension or Magento 2 extension you get the following error message, e.g. if you try to login the Magento admin backend:
The solution is in most cases very easy:
Mage registry key <...> already exists
The solution is in most cases very easy:
Please confirm that you followed all installation steps that are mentioned in the README
file of the module. Especially assure that the Magento cache is cleared, e.g. by emptying the var/cache/
directory in a Magento default installation and that the Magento compilation process has been triggered (if enabled).