It's necessary to start the CES to get the scheme names.
I made a sample script.
This script runs CES on the background and gets the scheme names.
Please run a script on the Expedition.
Get_Scheme_List.zip 1.5 KB
I have just tested your script. Yes, it does work.
Two prerequisites are:
1. CES should be connected to PCB (rather then Net Classes and Clearances)
2. CES should be started.