I’ve been working on removing a plugin made my Mageix called IXCBA.  It’s a Checkout by Amazon plugin that has a ton of problems and poor support.

After finding every instance of ‘ixcba’ in the database and code, I was still unable to get the backend of the website to come up.  Clearing out /var/cache and /var/session did nothing to help.

Turns out, sometimes just clearing those two doesn’t really clear all the cache.  After doing the process below, I was able to get right in to the backend with no problems.

Steps to Fix Magento Registry Key Already Exists Problem

Create a file called ‘index_clearcache.php’ in the root of your Magento installation.

Copy the index.php file into this new file.

Add to the end of the file these lines:


$app = Mage::app();
if ($app != null)
{
$cache = $app->getCache();
if ($cache != null)
{
$cache->clean();
}
}


This code must be at the end of the file in order to work correctly.

Save and upload this to your Magento root, then run once. It should have you back up and running!