I have a package which creates a scheduled job using a post-install script, and saves the id in a custom settings entry. I am trying to create the equivalent uninstall script, but not having much success. The class and associated tests all perform normally when I run them in the IDE. When I run them from the Web UI however, the abortJob call doesn't delete the job and my tests fail. If I comment out the tests and do an actual install and uninstall of the package, the scheduled job is not deleted.

Any idea why this would happen? I know that the documentation indicates that uninstall scripts cannot schedule new jobs, call @future methods, etc, but it doesn't mention anything about deleting existing jobs. The same code, when part of a controller for a settings page, worked fine. Maybe I am misintepreting when the uninstall script actually runs, meaning the only option is for an admin to delete the scheduled job manually, before trying to uninstall the package?

Code snippet:

...

if(settings != null) {

  try {

    system.debug('Removing scheduled job with id: ' + settings.scheduled_job_id__c);

    System.abortJob(settings.scheduled_job_id__c);

  } catch (Exception e) {

    system.debug('Error removing scheduled job: ' + e.getMessage());

  }

  delete settings;

}

...