Another "Could not AOT the assembly ..."

Hi,

I'm facing a "Could not AOT the assembly"-Error without any errornumber. The solution works fine on Android, Windows Phone and iOS iPhoneSimulator. But trying to deploy it to iPhone devices it comes to the error.
I have tried all 3 "Linker behaviors", Release and Debug and also LLVM on/off. I have 2 iOS devices (iPad 2 and iPhone 6) with the same error.

Any ideas ?