MIT Events Calendar - Why can't I edit an event for my department or group?
First, be sure you have the proper permissions to create and edit events for your department or group. If you're not sure, check with the Events Calendar team at calendar@mit.edu.
If you do have the right permission, it's possible the person who created the event did not add a Department/Group filter. In this case, the original creator of the event will need to edit it. They should add your department or group name to that field as well.