App hangs on splash screen [Screenshot]

Hello,
I had to install Unity after a while because App Store asked me to update my game to support iOS x64. I managed to recompile the game using Unity 5. It runs fine but I soon discovered that the main plugin I was using is not working fine anymore because of the new physics. So I built it again using Unity 4.7

Export was fine, but compiling with XCode (latest version 8) was giving some errors. I have no physical device, so changing the SDK version on player settings to simulator made all compiler errors disappear.

The app builds but it hangs on splash screen.

• How do I solve this?
  
  
• Changing device to Simulator will allow me to publish app to App Store?

Thanks

 

Up. Still didn't manage to fix this.