In my AWS account I can see around 8 ECS instances are running since several months and those cannot be drained, therefor it incurs more cost to my AWS account.
Even when I try to drain it shows the following error,
Even when I try to check them from EC2 console, those are not available. Therefor I have no idea how to delete them before incur more cost.
Can anyone help me how to drain all those old ECS instances ?
Thanks.

