I was migrating one field to another today and I got this exception when trying to delete the old field from the Fields tab: “Cannot delete this field because it is referenced by other objects”.
Not a great error message, but it means that “You can’t delete this field because it is referenced in the Layout tab”.
Here’s how to fix this:
1. Open the WIT. Go to the Layout tab.
2. Find the reference to the field that you are trying to delete. In my case I was trying to delete Project.ITRNumber. As you can see it was still being referenced in the Layout…which is why I couldn’t delete it from the field list.
3. Either change or remove that control from Layout. In my case I changed it to MSN.LSE.ITR rather than deleting and recreating the control.
4. Go back to the Fields tab.
5. Select the field you want to delete and click the Delete button from the toolbar.
It should delete the field now.