I was having a project developed in OpenChurch. I made changes so that the project fits my church's needs. I am still playing with how to upgrade openchurch, and come up with some error. I was trying to update the distribution and drupal core. First, I used command 'drush dl openchurch' and it works nice, upgraded openchurch to 7.x-1.11. But the drupal core is still at 7.12, and I want the core to upgrade to 7.17. Then I use command 'drush pm-update project drupal-7.17'. After upgrading, the drupal core seems to upgrade successfully, but openchurch is broken. I open my site and it shows drupal components well, but page content is empty, and a message saying 'The requested page "/openchurch/" could not be found.'. As shown in the image below:
May I know what might go wrong and how to fix it?