Customer is not able to cancel a change order.
Even he adds a cancel status, the "save" button is disabled when he sets the new status as 'Cancelled'
Service Desk Manager 14.x
There was a custom function preventing the "save" button to be enabled when the status were different from the pre defined status list
For the first part of this case, the problem was that there is a custom function that prevent the botton 'save' to be enabled for specifics status. After modifying the custom code, you were able to save the change order after changing the SO status to 'Canceled'.