Got the same issue using Unity 5.4.2f2.
It's a really severe issue for us. Please fix.

In case this helps anyone - I raised a similar issue where the iOS device (iOS 10) the UI appeared locked and display distorted on resuming app after extended sleep (see https://fogbugz.unity3d.com/default.asp?846895_82ts9nnt8gm5rp25 ).

The quick workaround I used was to modify the Unity generated UnityAppController.mm:

- (void)applicationWillEnterForeground:(UIApplication*)application
{
::printf("-> applicationWillEnterForeground()\n");

// applicationWillEnterForeground: might sometimes arrive *before* actually initing unity (e.g. locking on startup)
if(_unityAppReady)
{
// if we were showing video before going to background - the view size may be changed while we are in background
[GetAppController().unityView recreateGLESSurfaceIfNeeded];
}

//
// Bug workaround:
// On returning from device sleep mode, Unity UI is lock and will not respond
// If the device is rotated, Unity will 'wake up'
// So force landscape orientation to wake up Unity
//
[[UIDevice currentDevice] orientation];
NSNumber *value = [NSNumber numberWithInt:UIInterfaceOrientationPortrait];
switch( [[UIDevice currentDevice] orientation] )
{
case UIDeviceOrientationPortrait:
value = [NSNumber numberWithInt:UIInterfaceOrientationPortrait];
break;

case UIDeviceOrientationPortraitUpsideDown:
value = [NSNumber numberWithInt:UIInterfaceOrientationPortraitUpsideDown];
break;
case UIDeviceOrientationLandscapeLeft:
value = [NSNumber numberWithInt:UIInterfaceOrientationLandscapeLeft];
break;

case UIDeviceOrientationLandscapeRight:
value = [NSNumber numberWithInt:UIInterfaceOrientationLandscapeRight];
break;
default:
// setting to portrait does not work
// value = [NSNumber numberWithInt:UIInterfaceOrientationPortrait];
// but forcing the device into landscape mode and then allow it to auto-correct works
value = [NSNumber numberWithInt:UIInterfaceOrientationLandscapeLeft];
break;
};
[[UIDevice currentDevice] setValue:value forKey:@"orientation"];
}

Reproduced this issue in iphon5s, iphone6, etc. with Unity 5.3.4f1

pls fix..

On a current game we are developing we are seeing a solid color full screen when we run on new iPhone 7 Plus. Have people seen this problem manifest as it hanging with the background color filled in but before the full opening scene has been rendered?

Workaround: In the info.plist file, go to "Supported Orientations" and add portrait (I also move it to index 1 instead of 0). This will fix the screen issue but mess the splash screen up on some devices. This fix worked for me, so from what I can tell if you make a portrait version of your Splash Screen art (Rotate it 90 degrees).

I added both images to the splash screen in Unity Player Editor and they appeared in my Xcode project file. Go to "Launchscreen-iPhone.xib", once you have selected a canvas and the XIB has loaded, click the bottom where the screen measurements are. This will open the device and orientation selector menu make sure you have it set to portrait.

Now head to the hierarchy and and create a new View and call it something like "ViewP" (you can add things to the xib by using the toolbox in the bottom right, for those who don't use Xcode), on the right enter the attributes selector, scroll to the bottom where it says "Installed", uncheck that and hit the small plus symbol to the right, if you have the view set to portrait, just click Add Variation, this will set the view to only activate in portrait screen.

From there add an Image View and change the "Image" option in the attributes selector to your portrait image. I'm not 100% on what I did with the constraints but essentially what you want is to have it stay the same through all the different screen sizes, from there you should be good!.

Hope this helps folks. Cheers.

Having the same issue with + devices in Unity 5.4.2f2 personal edition. Currently testing a work around in Xcode. Will re-comment if the test is successful

Guys please vote for this to be solved, dont just comment

Having the same awkward issue!

Please fix, this is a stupid issue that should not exist

Also does a mini glitch sometimes on Android.. FIX this ASAP!!!