Can't create Change Set

[joewarrenmeeks]

Hi there,
I'm trying to set this up using the links you provide below, but I can't complete the setup. I get a message saying:
Check the following transforms: ["AWS::Serverless-2016-10-31"] You must use a change set to create this stack because it includes one or more transforms.

But when I click the Create Change Set button, nothing happens and Execute is still greyed out.

Am I missing a step?

-- joe.