Patch 10415 404 errors
After installing patch 10415 404 errors my be displayed instead of regular sites on your Magento 1 shop. I show you all your need to know about this problem and also how you can solve it. Please take your time and solve this instead of not installing this security patch!
Patch 10415 404 errors
The 404 error page you see is Magento standard error page from errors folder. It is displayed, because one of your 3rd party modules generates a PHP Warning or Error that cannot be handled by Magento. You can find the following text about this known issue in your Magento documentation:
Magento is not properly logging PHP warnings that occur early during page initialization. Instead, of logging the error and continuing operation, Magento generates a 404 page. (Previously, Magento logged these warnings in the system.log file, and execution would continue as usual.)
Finding the problem
The simple task is now to find the 3rd party module, that creates this problem. There can also be more than one, so it is a quite simple task to deactivate modules one by one by changing /etc/modules XML files. Just replace true with false and reload your site (on development system with turned off cache!). Only test 3rd party modules and no Mage_ modules, because the error won’t be there.
If you get a valid page, you should restore all files back to normal, instead the last one. If you reload the page again and it shows correct content, you found the 3rd party module, which generates this error.
Fix this problem
Fixing the problem depends on how good are your PHP skills. The first and easiest possibility is to install the current version of this module. May this problem is already fixed in a current version. If not, you should roll back your patch commit and find out which kind of error or warning is generated by this module and fix this. This can be anything. My problem was a xml error in config.xml – which is the hardest thing to find out.
Conclusion
Patch 10415 may result in 404 errors, which always comes from 3rd party modules. You can find and fix this error.
