Now I did more tests. It runs well on every device I’ve tested in every configuration (even in arm64) when built on Development configuration. When built on Shipping (production) configuration, it works well on armv7 but not on arm64. Maybe I can have better chances building remotely from a PC? Maybe it’s a problem with libc++? or libstdc++?
When I retrieve the Container of the app, the Logs folder is not even created. So I don’t have an UE log for this, I think it crashes before creating any UELog.
To reproduce I package the project with C++ code with a Mac with 10.11, Xcode 7.3. I’m using the File->Package->iOS command on UE4. I’ve not yet tested this with another project.