What makes a layout invalid?

Hi Guys.

I am in he process of making some layouts. I keep getting the message: This Layout is invalid and should not be scheduled.

What makes the layout invalid?
What is invalid about it?
How do i fix it?

The most common cause for the layout being invalid, especially on the CMS level is an empty region.

When you create a new layout it comes with one full screen region, perhaps you add new region and content to them, but left the initial region empty?

If you can’t see why it is invalid, please export the layout and send it over to me via private message.

Hi Peter.
Thanks for your response.

That was exactly the problem!! I no longer have this issue!
Thank you
Saff