Managed Nodes - Deregister This Managed Nodes is Grayed Out

Hi, The "Deregister This Managed Node" option is only applicable for hybrid-activated machines, not standard EC2 instances. Hybrid-activated nodes are typically identified with IDs in the format "mi-012345678."

Reference Documentation: https://docs.aws.amazon.com/systems-manager/latest/userguide/systems-manager-hybrid-multicloud.html

https://docs.aws.amazon.com/systems-manager/latest/userguide/hybrid-multicloud-ssm-agent-install-linux.html

https://docs.aws.amazon.com/systems-manager/latest/userguide/hybrid-multicloud-ssm-agent-install-windows.html

The "Deregister This Managed Node" option will only work if the agent was installed using the hybrid activation method described in the documentation above.

Troubleshooting Deregistration Issues:

If you're unable to deregister a hybrid-activated machine, try the following:

On the server, clear the previous registration:

Open PowerShell as Administrator

Run the following commands:

cd\

cd "C:\Program Files\Amazon\SSM"

.\amazon-ssm-agent -register -clear

In AWS CLI or CloudShell, deregister the instance:

aws ssm deregister-managed-instance --instance-id "mi-0d123546758"

Please let me know if you need further assistance.