What does Requires capabilities : [CAPABILITY_IAM] mean and how do i activate this?

Question

Following this tutorial on AWS instance scheduling, I was able to create a new EC2instanceScheduler cloud formation stack.

However, each time that I try to update that stack, the following error occurs:

Requires capabilities : [CAPABILITY_IAM]

I've searched for information, but can't seem to find any clear information on what this is, what this means and how to activate this.

On this page, Amazon says the following:

In some cases, you must explicitly acknowledge that your stack template contains certain capabilities in order for AWS CloudFormation to create the stack.

But I can't seem to understand how and where. Can someone give me clear information on this subject? What does this error mean and how do I solve this?

Answer 1

It's very easy to miss, and I've seen others missing this part too.

In step 4 (review) of the update stack, at the bottom, there is this little checkbox that has to be checked before you can update the stack.