"Failed to start the instance. Insufficient Capacity" error

Insufficient instance capacity covers the steps that you can take to address the error you can getting.

• I would also recommend checking out Why am I receiving the error "Your requested instance type is not supported in your requested Availability Zone" when launching an EC2 instance?
• You can run aws cli commands to get which Availability Zones, Azs can run your instance type
• Try running your workload over multiple AZs.
• On-Demand Capacity Reservations enables you to reserve compute capacity for your Amazon EC2 instances in a specific Availability Zone for any duration

Occasionally, demand for certain instance types can be so high that AWS does not have sufficient capacity at the moment you request it. In that case, you have several options:

1. Use a different instance type if you need immediate resources, and switch back to the preferred instance type later;
2. Try launching the instance in a different Availability Zone;
3. Wait a few seconds and retry;
4. Consider purchasing Reserved Instances if you want the greatest likelihood that the specific instance type will be available to you in your preferred AZ when you request it.