Policy Actions can be configured to start EC2 instances using the AWS API. After attempting to start an instance (and after receiving a good response from the AWS API call to start) a 40 minute wait timer is invoked. This wait time is to allow for the instance state to settle and for normal state collection to complete and reflect in our platform. After the timer runs out the instance state is checked. If the newly started instance is not in a running state at that time then the the action is marked as "Failed" and an "Instance(s) not Started ..." message is displayed in the Action results. This message is followed by the instance id or list of instances ids and their accounts of the failures.
The following steps should be followed to troubleshoot: