App works fine in preview app, but crashes in iOS

I have been noticing more and more discrepancies between AppGyver’s preview app and what the final build looks like in iOS. It started with minor things like formatting (works in iOS, doesn’t work in preview app). Now I’m getting more serious issues where the app behaves correctly in the preview app, then crashes on the iOS build. As you can imagine, between AppGyver’s build time, uploading to Apple, then waiting for processing to finally access it in TestFlight, this process this takes quite some time only to realize that the app just crashes on certain pages.

Any one else experience similar issues?

Hi @Steve_Thomas, sorry to hear this is happening with your app. What kind of crashes are you experiencing on iOS, does the app crash upfront or is it related to some action taken in the app? If you don’t get an error message but just a crash of the app, you can capture the device logs with the iPhone connected to a Mac using Xcode (Window → Devices and Simulators).

Through some extensive testing I was able to figure out that some old formatting code was causing the crash. Prior builds (3.X and before), you were able to assign icons as null through formulas (if you did not want the icon to appear for certain conditions). On current builds, you need to assign them as “” in the formula, as null will cause iOS to crash.

I was not getting an error message, but that’s a great tip regarding using a Mac using Xcode to check logs.

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