I checked the boards and see that there is a reported issue with FileMaker Pro 16.04/05 and MacOS crashing, but nothing specific to the FMGo iOS SDK, hence my post. Yesterday, I packaged our FMGo database with the latest iOS SDK (16.04, Xcode 9.2 as instructed). Upon release this morning, I have had numerous reports of the app crashing. After the initial crash, it is irreparable and any data not synced is lost (it simply crashes over and over again). I then tested the build on my iPhone and it followed similar crashing behavior.
Fortunately, I held onto a version that was built with the iOS SDK 16.03 (don't recall the exact Xcode build), and it appears to work without crashing. I will be pushing that version to devices at days end to hopefully avoid this continually occurring. All devices that are reporting crashes to me are iPad Mini 4's running iOS 11.2.6 (Build 15D100). As mentioned, I also tested on my iPhone 7 running the same iOS.
I subsequently loaded the database into FMGo on my iPhone to test independent of the iOS SDK packaged app. Results indicate it works as expected without crashing, at least on my iPhone. The native FMGo version is 16.04. I will concede, however, that I did not extensively test this scenario. When using on my iPhone the iOS SDK app crashed almost immediately. I was able to use the app thoroughly without incident in native FMGo 16.04.