In some cases, host creation on AWS may fail due to various reasons. Here are a few things to check when the host creation fails:

1. Check if Docker Engine and Nirmata agent were successfully installed and started on the instances provisioned on AWS. To check if Nirmata agent is running, ssh to your AWS instance and use command: sudo docker ps. This command will list all the running containers. Verify that the nirmata-agent container is running
2. If Nirmata agent is running on your AWS instance but the state displaying on the Nirmata console is ‘Pending Connect’ or ‘Not Connected’, the Nirmata agent might be unable to connect back to Nirmata server. Verify that AWS security groups for your instance allow outbound HTTPS traffic. You can check be accessing a website e.g. www.google.com using curl or wget (e.g. curl -XGET https://www.google.com)
3. When creating AWS instances using Launch Configuration mode, ensure that the network selected in Nirmata is the same as the network of security group configured for the launch configuration. If this is not the case, instance creation will fail.