From the Demo instructions:
Reminder: If you restarted your SAS session, you must recreate the PG1 library so you can access your practice files. In SAS Studio, open and submit the libname.sas program in the EPG1V2 folder. In Enterprise Guide, run the Autoexec process flow.
Note: If you did not create the libname.sas program, complete the Activity: Create a Library for This Course (REQUIRED) in Lesson 2.
Hope this helps!
Mark