EC2 launch failure with ASGs

I have an EC2 launch-template that I can create individual instances from, but when I try to create then in an ASG they die as soon as created. is there a guild to trouble shooting, or at least getting more info as to why they are failing?

Typically a sign of a health check failure. You’re attaching them to a load balancer?

If they die in seconds, rather than 1-2 minutes, it’s also worth checking if you’re launching them with PIOPS. My recollection is that’s also the behaviour if you have hit your PIOPS or other EBS account limit.

https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/troubleshooting-launch.html

Thanks all, it was that my custom KMS key lacked the “kms:GenerateDataKeyWithoutPlaintext” action for the autoscaling resource role