Cannot start notebook. Platform identifier (notebook-al2-v2) is not supported for this service.

This error is occurring because the notebook-al2-v2 platform (which supports JupyterLab 3) has been deprecated. As of June 30, 2025, you can no longer create new or restart stopped JupyterLab 1 and JupyterLab 3 notebook instances.

Unfortunately, recovering files from a deprecated SageMaker notebook instance that cannot be started is challenging. SageMaker notebook instances use EBS volumes to store data in the /home/ec2-user/SageMaker directory, but these volumes cannot be accessed from outside the SageMaker notebook instance when it's not running.

Here are your options:

1. Contact AWS Support to request a grace period for your deprecated instance. If granted, you could temporarily access your notebook to migrate your data.

2. If you previously set up any backup mechanisms like copying your files to an S3 bucket, check if your data is available there.

For future reference, to avoid losing data, it's recommended to:

• Use code repositories to maintain your code and notebooks
• Store your data in separate storage services like Amazon S3
• Implement regular backups using either the notebook terminal or lifecycle configuration scripts
• Consider implementing disaster recovery solutions for critical SageMaker workloads

Going forward, you should migrate to JupyterLab 4 notebook instances (platform identifier notebook-al2-v3) to ensure you have a secure and supported environment.
Sources
Files recovery in Sagemaker Deprecated instance | AWS re:Post
JupyterLab versioning - Amazon SageMaker AI
Amazon Linux 2 notebook instances - Amazon SageMaker AI