I tried searching on FBSOpenApplicationServiceErrorDomain
and every instance I found, none of which really helped with solving it, was to do with the simulator, such as people encountering it only in the simulator.
If so then the error on real hardware might be different – FBSOpenApplicationServiceErrorDomain
might be a red herring. You might need to test on an iPhone 5 to see the actual problem. It obviously could be due to the CPU being 32-bit and so running code in your app that is ignored by anything more recent. Or possibly the OS which is iOS 10 or older.
Frankly you are going above and beyond trying to support so old a device and OS. I think that, for Apple OSes at least, targeting the current and last version of the OS is the most you should do. E.g. in June Apple reported that 92% of iPhones were on the then last two versions of iOS. Most of the other 8% will be older devices which cannot be upgraded, and their users will be used to apps also not getting upgraded.