Problem in EC2 image creation

When you create an AMI from an instance, Amazon EC2 powers down the instance before creating the AMI to ensure that everything on the instance is stopped and in a consistent state during the creation process. If this is causing an issues you may want to manually shutdown the instance and create a snapshot that you then turn into an AMI.

The below link has details on how both turn a running instance into and AMI and how to turn a snapshot into an AMI.

https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/creating-an-ami-ebs.html