Following on from what Danny says, whatever the name of your layout files the important thing to remember is that the the have to contain the elements declared in the list in the theme's config file. For example, if only one block region I'd needed, then that block region needs to be in the layout file, otherwise it will throw an error that will break the theme.
Themes
2 Settings Pages?!? Moodle 2.7.2
This discussion has been locked so you can no longer reply to it.