App Crashes Only On Testflight Build

Question

I have created an app on swift and tested it extensively using iPhone 6, iPhone 6 plus and iPhone 5 devices and all the simulators offered in Xcode. The app runs fine and do

Answer 1

I guess its a swift compiler issue. To verify first go to Edit Scheme then change the Build configuration to Release mode in Run tab and then install the build locally. You will get to know where exactly its crashing.