I recently inherited a Drupal 7 (7.39) site using an old version of Omega 4 (beta7) and a custom subtheme. All was well until this morning, when cron got stuck. It unstuck itself before I could start work, but now Drupal no longer recognizes the Omega base theme, so classes and other theme variables are not inserted properly, and the display is a mess.
- I have cleared all caches from admin_menu and Devel many times (we are on shared hosting and there is no shell/Drush access).
- There are no unusual errors or warnings on the status report or watchdog.
- There have been no configuration changes within Drupal or on the server, which is running PHP 5.5.29 and Percona 5.6.28.
- There are no Omega- or other theme-related modules installed except CiviCRM Theme, which I have disabled to no effect.
- The files are all still present in /sites/all/themes/omega and /sites/all/themes/oursubtheme , and completely untouched as far as I can tell (no changes in file sizes or date stamps for as far back as we have snapshots).
- As it's shared hosting, all files are owned by the account user with permissions set to 775. Again, this is not something that has changed.
- the subthemes (both Ohm, the bundled subtheme, and our custom one) show up on the /admin/appearance screen just fine, but Omega itself does not.
- I can get to the settings screens for the subthemes, e.g. /admin/appearance/settings/ohm, just fine. But browsing /admin/appearance/settings/omega returns an Access Denied error.
- But Drupal must know that Omega is installed, because when I look at /admin/reports/updates or /admin/appearance/update, it shows up on the list of themes with updates available.
- The pending updates for Omega are not security-related, so I don't think that it is a situation where it is being disabled or disallowed by a security mechanism
Naturally, the timing could not be worse for this to happen to the client, so I would appreciate any ideas as to what could cause Drupal to "lose" a theme like this, or how we might jog its memory.