@AndyMenon How many Keywords have you provided in the Keyword Based Classifier? How many pages does your PDF contain ? The Intelligent Keyword Classifier is available starting from the latest release. I was able to get the Document Understanding Framework to work by using Omni Page OCR with a Scan Profile and use Keywords from the Document that appear to be constant in those types of document throughout.
I’m not sure if the Intelligent Based Classifier is really needed for your data extraction 