Cast Modulated Shadows causes black screen on iOS with non-default FOV

Using a FOV other than 90 with Cast Modulated Shadows seems to cause a black screen and weird FOV issues on an iOS device, in 4.9.2.

Here is a bare bones [test map][1], containing just a static mesh box for the floor, a playerstart, and a default DirectionalLight with CastModulatedShadows being the only property changed. There is also a default camera pointing down that’s set to auto-activate.

If the camera has FOV=90, it works fine on the iOS device. If the camera has FOV=60, there is just a black screen.

While the screen is black, if you double-tap the home button on the device (app-switching mode), or swipe from top of screen (to show the notification pull down), and then return to the game, it appears to render as normal. Also note that if you tap 4 fingers and use the RestartLevel console command, the level will reload and then start flickering between FOVs really weirdly (but if you go into app-switching mode and back again it fixes itself).

The device is an iPhone 6 Plus on iOS 9.0.2. Both scenarios work fine in the previewer. (41.6 KB)


We’ve entered a bug for this issue, it’s referenced as UE-22117. If you’d like to check on this bug in the future, please feel free to reply back here and we’ll provide you with an update.

Thank you and have a nice day!

Hi I can’t reproduce this issue in either 4.9 or our pre-release 4.10 code on an iPhone 6 running iOS 9.0.2. Do you have another iOS device to try? I’m wondering if it’s specific to the 6 Plus for some reason.

Hi ,
It seems like it could be specific to the 6 Plus - I just tried it on iPad 3 and the problem does not occur there.

I downloaded and installed a clean version of 4.9.2 (needed to for other reasons anyway… somehow I’d managed to change all of the engine Pure function parameters to “By Ref” in a BP only project, but that’s another story), and removed intermediate/saved from the project dir, removed data from the iPhone 6 Plus and installed the test map clean there, and it still occurs.

Is there anything else I should delete in the project or engine dirs to ensure what I’m installing to the device is a completely clean, brand new cook with zero cached data?

I should also mention this is from the editor, not frontend.

I’m setting up a 6S Plus this weekend too, so if I get around to trying it on there I will report back.


Are you able to try it on a 4.10 preview release? We believe the issue is fixed there and it would be great if you could confirm.


Hi , the problem no longer occurs in the test map on a 6S Plus in an unmodified 4.10 preview 3 (I don’t have the 6 Plus any more to test on).

Glad to hear it. Thanks for confirming.