Steps to reproduce:

1. Prepare test eZ Publish 5.4 installation, fully updated;
2. On the admin siteaccess, create a new folder in content tree:

Name: "Tests"
Location Id: 122

3. Edit /ezpublish/config/ezpublish.yml:

ezpublish:
    system:
        ezdemo_site_group:
            content:
                tree_root:
                    location_id: 122

4. On the admin siteaccess, go to /content/urltranslator and creat a new global URL alias:

URL alias: myalias
Destination: ezinfo/is_alive

5. Go to "http://example.com/myalias". Instead of being automatically re-directed to "http://example.com/ezinfo/is_alive", a "Module not found" error page is displayed.

ezpublish/logs/prod.log:

...
[2015-09-28 18:03:46] app.DEBUG: Router eZ\Bundle\EzPublishLegacyBundle\Routing\DefaultRouter was not able to match, message "" [] []
[2015-09-28 18:03:46] app.DEBUG: Router eZ\Bundle\EzPublishCoreBundle\Routing\UrlAliasRouter was not able to match, message "Could not find 'UrlAlias' with identifier 'Tests/myalias'" [] []
...