This is an absolutely abysmal bug - This is not fixed even in 5.5p1. The game crashes when unlocking your phone if you've gone into portrait mode. Iphone 6 with iOS 10 here. Run game which is landscape. Lock phone. Turn phone into portrait while locked. Unlock the phone and the game crashes. It doesn't crash if you keep your phone in landscape and unlock that way.

I have noticed that the severity of this issue is 3, meaning "workaround is possible", which absolutely not the case.
So please increase the severity of this issue, and fix it asap. It is really a terrible bug!

None of the posted workarounds works for our situation, but we came up with one that does!

Here's a link to the basics of our current workaround: https://gist.github.com/Ethan-VisualVocal/286ebae00eb3100885b19c90e8b9ff52

Context: Our app starts in Portrait, has autorotate disabled, and we explicitly force LandscapeLeft upon loading a "level" -- this step of explicitly changing from Portrait to LandscapeLeft causes the bug to appear almost 50% of the time on iOS 10.

Though, this causes wired auto rotation for our users when they bring our game front Background to Front, That's wired, and I dont know if Apple will reject our app because it behaves strange, just like a bug.

Hope this bug would be fixed soon.

Thanks to FSPARK's workaround, but the code will till crash our app.
After digging in our game, I found the app only crashes in this situation:
(Our game only supports landscape left and right)

1. Open your game
2. Get in any scenes which is somewhat complex.(Very simple scenes does not crash in our game)
3. Lock your iphone.
4. After ApplicationDidEnterBackground, unlock your iPhone with portrait orientation;
5. Game crash.

And with FSPARK's code, the app still crash when you set the device orientation to the same when you lock your iPhone. The screen do not auto rotate to wakeup Unity.

So we changed the code a little, to always rotate the app to the opposite landscape, and the app does not crash any more. Here's the code:

UIInterfaceOrientation interfaceOrientation = [[UIApplication sharedApplication] statusBarOrientation];
NSNumber *value = [NSNumber numberWithInt:UIDeviceOrientationLandscapeRight];

if(interfaceOrientation == UIInterfaceOrientationLandscapeLeft){
value = [NSNumber numberWithInt:UIDeviceOrientationLandscapeLeft];
}else if(interfaceOrientation == UIInterfaceOrientationLandscapeRight){
value = [NSNumber numberWithInt:UIDeviceOrientationLandscapeRight];
}

[[UIDevice currentDevice] setValue:value forKey:@"orientation"];

if you dont vote for it, it wont be fixed. Just commenting here doesnt help

Unfortunately, we just got our first submission rejected by Apple over this.

Since this issue has been around since iOS 10 shipped, I guess we will have to try FSpark's workaround!

Voted.

Everyone please vote, don't just comments, there are only 9 votes left to raised this issue to Unity

Does anybody have found a proper fix for it. Have unity fixed this issue in some version above 5.4.x series? I am also stuck in this. It should have been answered or handled till now.