Review the error message
The error typically appears in this format:

botocore.exceptions.ClientError: An error occurred (UnsupportedOperation) when calling the StopInstances operation: You can't stop the Spot Instance {Instance-ID} because it is associated with a one-time Spot Instance request. You can only stop Spot Instances associated with persistent Spot Instance requests.

Understand why the error occurs

• AWS prevents stopping one‑time Spot Instances.

• Flexera Ocean stateful nodes use lifecycle actions that don’t rely on AWS Stop.

• Calling StopInstances directly results in an UnsupportedOperation error.
  
  

Use Pause/Resume instead of Stop
Flexera recommends that you use Pause and Resume instead of trying to stop the instance through AWS or automation.

• Pause terminates the instance but keeps the resources you choose to persist.

• Resume creates a new instance and reattaches those persisted resources.

This gives you the functional equivalent of stopping and starting the instance.

Confirm resources you want to persist
When pausing a stateful node, you can keep:

• Network interfaces

• Volumes

• Snapshots

• AMIs

Ocean reattaches the preserved items during the Resume action.