KBEC-00296 - Error occurred during configuration EC-EC2 plugin creation- Test connection failed

I am trying to create configuration for the ec-ec2 plugin and getting error with message "Error occurred during configuration creation: Test connection failed", but it’s hard to find what causes this error message.

Find commander.log(Please see this KB to find exact location of your log:
KBEC-00173 - Default locations and use scenarios for CloudBees CD (CloudBees Flow) log files

Try to find log something like "Couldn’t resolve host: java.net.UnknownHostException: BR-MAC-5"

If you found this, this means your server can’t reach to the resource that you’d like to add at your configuration.

Resolve your network configuration at your OS level will resolve this issue.