AWS Launch Configuration error: The requested configuration is currently not supported

Figured it out. My VPC was set to Dedicated Tenancy, which doesn't support all types of instances. The Dedicated setting was done in error actually. I deleted the VPC (you can't seem to change its Tenancy setting) and then created a new one, followed the steps for the Launch Configuration and the ASG created the instances without a problem.

I hope this helps someone someday.

There will be different answers to this question, but as Raf said a good place to start is your VPC, subnet, instance types, and AMI.

My issue was that AWS deprecated my instance type (m3) in my specific region. Easiest way to check is to go to the EC2 tab in AWS console and try to launch your specific setup manually.

I too, was facing this issue because my VPC was set to dedicated tenancy. The error message today is very helpful, in saying that

The requested configuration is currently not supported. Please check the documentation for supported configurations.

(without providing any link to this documentation). I wanted to link it here for anyone who is looking for it-

This page mentions that

Some instance types cannot be launched into a VPC with the instance tenancy set to dedicated.

Changing my instance type to one of those mentioned here fixed this issue for me. I did not have to create a new VPC with default tenancy, although that is also a good solution if you have the permission to do that.