pyesapi 16.1 issue with volume, DVH, ... calculation

[TmnGitHub]

Hello,

I am encountering some strange issues while executing my script. I have been following "Chapter 6. PyESAPI: The Python Interface to ESAPI" and this GitHub page. I am working on Eclipse 16.1

I am able to print the patient ID, last name, and first name for all patients. I can also print C1, but courses dose not show up. Additionally, I can print structure ID and DicomType, as well as ct.XSize and ct.YSize. However, I cannot retrieve the Image.np_array_like(), Volume, or DVH. When I attempt to run these, the process takes a long time and doesn't return any values.

Could you please recommend how I can resolve this issue? My goal is to successfully run Code 6.19 from "Chapter 6. PyESAPI: The Python Interface to ESAPI." which dose the Bulk Extraction of volume, DVH, ...

Thank you in advance for your time and help.