Do you mean import fails without script?
i had this ver same problem. What you need to keep in mind is that FileMaker go does not have all the capabilities as does FileMaker Pro. Why you can import with FileMaker Pro. There is a trick to communicating with an offline solution through FileMaker using a connector file which opens your hosted solution. Through a relationship between host - connector file - iPad, you can exchange and update records. A little more involved in scripting but it does work. FileMaker has a nice p of how to do it. I put the link below.