This article provides a possible solution for the issue where you get a 503 error when trying to access Adobe Commerce storefront and/or Admin.
Adobe Commerce 2.3.x
Steps to reproduce
(Prerequisites: make sure the store is not in maintenance mode).
Navigate to your Commerce Admin or storefront in a web browser.
The page loads.
You get the HTTP 503 (Service Unavailable) error. The Apache
error.log includes the following message:
Invalid command ‘Order’, perhaps misspelled or defined by a module not included in the server configuration.
Apache 2.4 compatibility module
mod_access_compat is disabled, which results in Adobe Commerce URL rewrites not working properly.
mod_access_compat Apache module and restart Apache, by running the following as a user with ‘root’ privileges:
a2enmod access_compat service <name> restart
. On Ubuntu,