ConflictException

This error will occur when you try to create a resource that conflicts with an existing object. It can also occur when adding a member to a group that the member is already in.

This error can be caused by a request sent within the 8-hour idempotency window with the same client token but different input parameters. Client tokens should not be re-used across different requests. After 8 hours, any request with the same client token is treated as a new request.