Don't think it should. Mainly the demo is just helpful to demonstrate the proper way to use the tool since it's not designed to "out of the box" convert any Twine file automatically to Ren'Py. Things to try or follow up with me so I can help you troubleshoot:
- Open the Demo.html in Twine and note how it is formatted/laid out. Was your file written for Ren'Py or in a Twine format? (This will determine whether you should be enabling "Twine mode", or if you've already written it to work with Ren'Py.)
- Check that your Twine file is using the Sugarcube format for Twine 2.
- Check that all of your passages are connected.
- Note that the order of the passages is likely dependent on the order the Twine passages themselves were created. They should still be connected in the correct order using jump labels, even if they are not "chronologically" correct (there isn't a "reliable" way to determine this order without a lot more work, so it just orders in the way that Twine has ordered the file, which I have found is usually the order that you authored the passages).
- Does the Ren'Py script file run when placed into a project? If not, what is the error you are getting?