What gameplay feature is this bug affecting?
Trading

What's the issue? Please include any error messages you receive and as much detail as possible.
Getting an error that says: "You specified an invalid trade. Back to Trading Center?" on some of my lions.

Any links relating to this bug? For example, if a particular lion is bugging, what is the link to that lion?
https://www.lioden.com/lion.php?id=794178034443

https://www.lioden.com/lion.php?id=794178852974

https://www.lioden.com/lion.php?id=794178876766

https://www.lioden.com/lion.php?id=794178875564

https://www.lioden.com/lion.php?id=794178875565

https://www.lioden.com/lion.php?id=794179195142

Any screenshots you can provide us with?
https://i.gyazo.com/034cc1533a60d29ff6d2651d6c981987.png



Please provide us with step by step explanation how this bug happened so we can attempt to replicate it. If it's complex, please include screenshots where possible:
I made an offer on a trade and the trade was cancelled, but it says my lions are still being offered on a trade. Whenever you go to the trade offer link, it says: "You specified an invalid trade. Back to Trading Center?"