You can change the active roster for an event up until you make the first assignment. Once an assignment is made, the active roster is locked to the event. See About test assignments, and Edit a test event for more information. 

  • If no sessions have been created, administrators can undo the assignments by setting them to the default "Select Test Group" option, and the roster can then be switched.
  • If sessions have been created and testing has occurred, administrators will need to close the event and create a new event with the correct roster.