It seems to depend on layouts that are provided by a different module, NavigationLayouts. You can however choose a layout that is already available in your project, to keep things consistent. Open the pages in the modeler and in the properties pane you’ll find the option to change the layout. Also check the documentation here
Thank you for your answer. Did you mean that I have to change the properties in the OQL module pages? The Example_Overview, ExampleOQL_Result and ExamplePerson_NewEdit pages could not be opened.
So I can't change the properties.
Having the same problem, also following the Crash Course.
I got the exact same 6 errors although I'm pretty sure I did not remove the pages the errors refer to.
Edit: I found out I was using Mendix Studio Pro Version 9, this is causing problems with Atlas UI as far as I can tell.
Installing an older version 8 of Studio Pro 8 worked for me. Following the crash course I didn't noticed the reffering link in the documents was to the newest beta version of Mendix Studio Pro. This could be a bit clearer explained in the course :)