The Build Your First Workflow section of the training was developed as a standalone section that anyone can follow without having to download any materials. This means that the Example Workflows/TheData/Basics/Rooms.xlsx references a file from the Example Workflows folder that is shipped with every new workspace (unless fiddled with by the admins…) and is not part of the files.
We could indeed make this clearer in the slides to avoid confusions. The section is marked as (Optional) in the Powerpoint but it seems that’s not obvious enough. Would hiding the slides help – what do you think, Phil?