Solution 1:

If you know how to fix the source of problem (for example: change application settings in Beanstalk Environment variables or deploy fixed version of your application), then:

  1. Go to page Auto Scaling Group, choose your region, find Auto Scaling Group by Beanstalk Environment ID (like e-abcd12345).
  2. In Details tab, push "edit", set Desired, Min and Max to 0. Remember previous settings.
  3. In Beanstalk page, wait for message like "Removed instances [i-xxx, i-yyy] from your environment."
  4. Change settings or deploy your application
  5. Return Autoscaling settings back.
  6. Be patient, it may took 5-10 minutes to change Beanstalk health to "Ok".