You mean your project that you're using the framework for also has the script.rpy file for the DiscoFramework? Or you only copied over the screens.rpy and nvl_faded transform script into your project, as you wrote in your first comment?
Thank you for the clarification. Since the issue is persisting, I would recommend starting with the framework's script setup and adding (pasting in) your visual novel's custom scripts around it, rather than the other way around. This would help to avoid missing any lines of script that are being left out through the transfer.