If you are working with a school year and it does not appear in site-wide dropdown, your school year may not be published. To check this:
  1. Go to Core > Settings > School Information.
  2. Select the Years & Terms tab.
  3. Select the school year that is not appearing.
  4. Ensure that Yes shows next to "Publish".
  5. If Publish is set to no, click the Edit icon, and change Publish to "yes".