Why do UMG Widgets Flicker on iOS/Why are pictures blurry on iOS?

So two simple questions.

  1. When I package for iOS the UMG widgets flicker in game. Why? Is there a fix for this? (I hope)

  2. When I package for iOS the pictures are very blurry. Why? Are there settings that should be check or unchecked?

Here is the kicker: Both the widgets and pictures work perfectly on Android. Widgets only seem to flicker on iPhone 6’s and pictures are blurry on any Apple product. Weird I know.

Any help would be greatly appreciated!


Hello RickyDay,

I have a few questions for you that will help narrow down what issue it is that you are experiencing.

Quick questions:

  1. Can you reproduce this issue in a clean project?
  2. If so, could you provide a detailed set of steps in order to reproduce this issue on our end?
  3. Could you provide screen shots of any widgets and or materials that may be involved with this issue?

Hi Rudy,
I will try to reproduce this in a blank project if I can. My theory is the scale box is constantly adjusting which is causing the flicker. I read that in UMG you should first place a size box and then a scale box inside of the size box. I’ve done this and think it’s somehow causing the flicker. Ideally I want my widgets to scale properly for all devices but I am unsure how to do that?

I attached a short video for you to see. I also attached a picture of how my widget is structured. We have a scale box inside a size box so that it scales properly. If this is not the way our widgets should be structured please correct me. Ideally we need our widgets to scale for every device. I haven’t found an in depth tutorial on how to scale UMG widgets for all devices.

My buddy and I have recently pushed out 4 games on iOS but quickly received feedback that all of our games flicker. It doesn’t flicker on iPhone 5’s or Android. We really really REALLY need to fix this issue so that we can begin marketing and promoting our games properly. If there is a fix PLEASE PLEASE PLEASE let us know! We would really really like to start making money.


  • I though it was the event tick so we removed all of the Ticks in every UMG widget. Didn’t work.

Video Link:

Here is another low rez video of the flicker problem.

Thank you for the additional information. However, I will need you to answer the first two questions from my original post. These will help narrow down what issue it is that you are experiencing.

i have same problem. UE4.11
we test iphone6. iphone6s with metal API check.
if create many UMG widget (30~40). it filcking only one frame.
filcking all Texture ,Text , Material.

Hi Rudy,
To answer your first question, we aren’t sure how to reproduce it in a blank project because we aren’t quite sure what’s causing the problem.

As far as an order of steps to reproduce the issue, we could send you our project for you guys to check out. Would that be alright?


Hello ,

If you would like to provide the project I will take a look and see if I can narrow down what is causing your issue.

Hey Rudy,

and I did a lot of troubleshooting this weekend and managed to reduce the flicker significantly.

Along with removing all of the event ticks in our widgets:

  1. We added custom events in our level blueprints to call and add all of our widgets to the viewport. (At first we had them directly called on event begin play without custom events. I don’t think this was the issue though.)

  2. We then significantly reduced the amount of items in our widgets. At this point I don’t think UMG widgets can handle a lot of content without flickering or causing errors. (This is probably the issue!!! Don’t pack too much into your widgets.)

I don’t know if its just a MAC issue or if PC’s have this same problem?

Now we just have to figure out how to reduce the iOS package size, A LOT!

I am happy to hear that you have made progress with your issue. However, I was wondering if you still need/want me to look over your project in order to see if an issue is present that can/should be reported? If not I can convert your last comment to an answer to resolve this thread.

Yes that would be great! What is the best way to get you our project?

Hello RickyDay,

You could zip down you project and provide it via dropbox or google drive. This could be done here on the answerhub or in a private message to me on the forums.

Hello RickyDay,

After taking a look at the project provided, I was not able to reproduce the flickering on our end. I noticed that you said you had made some improvements. Was the project provided made after these changes were made? If so, could you provide an example of what I should be looking for? The project appeared to be working correctly on my end.

Really? Hm…That’s odd. You guys tested it on iPhones and there was no issues? Weird. When anyone plays it on an iPhone 6 it flickers. Even in the mobile preview it flickers.

Any updates Rudy? We’ve tried to do many workarounds but still have the same issue. It seems to be working without the flicker on iphone 5’s, but with the iphone 6, it flickers like crazy. did you test it on an iphone 5 or a 6? In the editor i believe it didn’t flicker for us.


Hello ,

I didn’t see any sort of flicker. I tested on an iPhone 6S with 9.3.1 as the OS version. I also tested this on an ipad air. I did not see any flickering. Could you double check the zip file that was provided to ensure that the issue is still happening in the project that was provided?

We’re getting the flickering as well, it’s worst if a scroll box is present, just scrolling up and down will flicker, sometimes it’s so bad the scroll box no longer response to input.

Hello polytopey,

Could you answer the questions that I asked of RickyDay?

Quick questions:

Can you reproduce this issue in a clean project?

If so, could you provide a detailed set of steps in order to reproduce this issue on our end?

Could you provide screen shots of any widgets and or materials that may be involved with this issue?

I encountered this problem today, but on a PC build, not iOS. I can’t speak for the others but the issue for me is caused when I have a specific UMG widget and call DrawMaterialSimple on a custom AHUD at the same time. I sent the repro case to you via PM on the forums.

For the repro project, if you run PIE then the 4 icons on the bottom of the screen show up normally but if you run standalone they don’t show up at all. They’re not flickering in this project for whatever reason, but the project I originally found this in they are flickering so I assume it’s the same issue.