Why can’t I modify my Amazon EC2 instance launch template?

Short description

Launch templates are immutable. After you create a launch template, you can't modify it. Instead, you can create a new version of the launch template that includes any changes that you require. You can create different versions of a launch template, set the default version, describe a launch template version, and delete launch template versions.

Resolution

Note: If you receive errors when running AWS Command Line Interface (AWS CLI) commands, make sure that you're using the most recent AWS CLI version.

To modify the launch template for an Amazon EC2 instance, create a new version of the launch template. To do this, you can use either the AWS CLI or the Amazon EC2 console.

Resolve UnauthorizedOperation errors

After changing the launch template, you might receive an error similar to the following one:

"UnauthorizedOperation "You are not authorized to perform this operation. Encoded authorization failure message.""

The UnauthorizedOperation error indicates that you don't have the necessary permissions to modify the launch template. To resolve this error, see How can I decode an authorization failure message after receiving an "UnauthorizedOperation" error during an EC2 instance launch? To add the required permissions, see Work with launch templates.

Review the restrictions for modifying launch templates

There are a number of rules that apply to launch templates. Review the Launch template restrictions to make sure that your modifications follow these rules.

Check the version number of your launch template

When you create a launch template, make sure that you're using the default version for the launch template. If you don't use the default version, then your changes don't take effect.