Error when adding a tracking number

[cost-less-uk8]

Hello, I'm trying to add a tracking number to a sold item but an error message appears when I click on submit. The error is 'Something went wrong. Please try again later.'. This needs to fixed urgently otherwise my seller performance will go down and customers will start to get impatient. Is anyone else experiencing this right now?

I have attached a screenshot of the error message.

[roger_roger_over_and_nowt]

As far as i know is you are using Simple Delivery you cannot add a different tracking number if sending by a different service but if you are using Custom Postage you can.

Which service are you using ?.