I would like to add that prior to purchasing logic pro I confirmed that I had all of the system requirements. My OS is Mojave 10.14 .6. Also the reason that I purchased Logic Pro X 10.4 Apple certified book by David Nahmani is because I had previously gone through Mary Plummer's book " Garage Band" Apple pro training series, also from Peach pit press. I got through this book with no problems with files or the lessons whatsoever. When I checked back at the lesson file downloads for the garage band book they are named as folders, whereas the file type of the file downloads for Logic pro X lessons are listed as aliases. That seems odd and I'm wondering if that could be why my lesson file are not behaving the way they are supposed to. The problem occurs in lesson 2, around page 76 at the point where a track has just been added to record a guitar part. When the track is record enabled I get the message: Volume "Logic pro10.4 lesson files are full" and I am unable to record. Bear in mind that I have all system requirements. When closing the project I get the message: " The document 02 get dancing logic x could not be saved, the file does not exist." I have copied the files to my hard drive as instructed, and retried that again in the hopes that the problem would be solved, eliminating any previous downloads, etc. If anyone, including the author David Nahmani, can think of a solution to this problem I would be very grateful!