I noticed that a few people where not entering any details into the APN Changer and then clicking Create Profile. This would create an invalid settings file and give an error message. I have added a few checks to the website so it will give a pop up on the screen if you are not entering any information into the form (or not selecting a country).
If your Carrier/Country is not listed please get in touch with me and let me know the Country/Carrier Name and the APN Settings so I can add it to the list.