Please can I remind you to check the status of an order on Magento before you add notes.
For example, if an order is at 'processing' and you need to add a note, please make sure that the status stays at processing once you've submitted the note. The status must remain the same as it was before you add notes.
Changing the order status will disrupt the orders process and may result in it being missed by the warehouse, or miss its delivery date.
If you have any questions then please contact me :)