Update nginx configuration TYPO3 introduced new URL’s for the backend. If you’re using an nginx, please add the following to your nginx configuration: Please make also sure, that no other nginx rule matches /typo3/ After updating your configuration restart your nginx or reload your configuration. You can find a full configuration example here:https://docs.typo3.org/m/typo3/guide-installation/master/en-us/In-depth/SystemRequirements/Index.html#nginx Update Apache… Continue reading TYPO3 11 Upgrade: Backend 404 not found