As I was adding items into a trade the other player had already cancelled. It still let me add the items but I then lost them. I went to restart the trade but the items are no longer in my inventory

Can you grab the ID?

If you click the link of the trade it should give you an URL/address that looks something like https://cartelempire.online/Trade/View/DDDAB807-F740-4ADD-894D-F5707E7D42C7 

(note to dev - my url above does not relate to the bug)

https://cartelempire.online/trade/view/4562F9A6-476F-4AE5-B82C-71C6AA466C61