Why can't I drag and drop a diary event?

You may not be able to move a diary event because the event has been aborted, cancelled, or marked as a 'no access' event. 

This means that the event no longer exists, however, the estimate or the job still does. If you need to rearrange this visit you will need to create a new diary event. You can do this by going to the 'view job' page and adding an event, click here for more information.