I will be investigating this issue today. I do appreciate your patience.
Could you tell me which version of iOS you have running on your iPad? 10.3.2 right?
Could you also tell me which version of Xcode you have? 7.3 right? and which version of Unity you are using?
I’ve been able to successfully test the Fetch Example in the StructureUnityAR.unitypackage with the following setup:
iOS 11.2.2 on an iPad Air 2
Could you please try to update your version of Xcode to something a bit newer as the newest version is Xcode 9?
My theory is that you will need to update your version of Xcode, as noted by the following articles:
I believe that you will need Xcode 8, at least, to be able to work with iOS 10.