Same problem as @kelway here, same questions - is this functionality only available in the non-free version?
I've tried many scenarios with both Tesseract and MODI - read from the web, read from Notepad, read from image, etc.
Different behaviors for Tesseract and MODI, though. For Tesseract flows, no errors are generated if run from the editor, but when run from the Flows panel I always get this error:

The MODI engine always appears to be created, but extraction always fails with this error from the editor:

or this one (or similar) when run from the Flows panel.

For further clarification: following the steps from this PAD OCR video (Tesseract) generates the error message shown above.