It looks like you may have started a custom layout and either never finished it, or deleted it after you assigned it to your homepage. What’s happening is that it’s trying to pull from a custom layout that’s either not there or doesn’t have any elements.
Keep in mind that you may be confusing some settings here. Currently it looks like you’ve gone to Settings > Reading > frontpage displays, and selected a “posts page” — Is this correct?
When you do this, you’re effectively telling WordPress that this is your “homepage” and so whatever you assigned as a homepage layout under Appearance > Theme Options > Content > Homepage is what it’s going to try and pull. If you’re simply trying to display a simple blog there, you don’t need any “posts page” and you don’t need the layout builder.
Go to the page that you’re creating as your “Blog” and apply the “Post List” page template. Then go back to Settings > Reading > Frontpage displays and make sure there is NO posts page selected.
Does that solve your issue?