Mage registry key “_singleton/core/resource” already exists in magento

Question

I am facing this problem on my site Mage registry key \"_singleton/core/resource\" already exists, Please help me how to solve this error.

I have checked the folder and

Answer 1

It is very important to clear the Compiler cache and after that turn it on in backend of Magento.

Clear the cache

SSH: find ./var/cache -type f -delete FTP: mrm -r ./var/cache ; mkdir ./var/cache

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Disable/Clear Magento compilation

SSH: php -f shell/compiler.php -- disable php -f shell/compiler.php -- clear FTP: mv ./includes ./includes.unused