Unable to start iOS app with UE 4.26

Development Platform & Builds Mobile
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1

I am using Unreal Engine 4.26 (but I am facing absolutely identical problem with Unreal Engine 4.25.3) on macOS Big Sur. I am able to successfully build the app from UE4Editor and to launch it on iOS device. However, that’s pretty much where things end - app gets launched and nothing but black screen is showing up. Log output in editor doesn’t suggest about any potential errors which might have happened.

I decided to try running app on my own from Xcode and launched iOS Xcode project from MyApp/Intermediate/ProjectFilesIOS/MyApp.xcodeproj. When opening the app I can see that everything in there looks pretty okay - signing is properly set as I configured in UE4Editor, also I am adding some additional stuff to Info.plist - those are properly added as well. App builds without any issues, all great. But when trying to run it on iOS device, I’m noticing this output in console:

2020-12-22 22:12:10.509618+0100 MyApp[7799:1892795] [UE4] Used memory before allocating anything was 45.03MB
2020-12-22 22:12:11.256143+0100 MyApp[7799:1892597] [UE4] Checking for command line in /var/mobile/Containers/Data/Application/E22CE553-DCD0-4B96-90F4-50EB019AC3EA/Documents/ue4commandline.txt... NOT FOUND!
2020-12-22 22:12:11.256291+0100 MyApp[7799:1892597] [UE4] Checking for command line in /private/var/containers/Bundle/Application/9E3E42D9-4F27-41A0-9E07-E4E28EAE0B4C/MyApp.app/ue4commandline.txt... FOUND!
2020-12-22 22:12:11.256615+0100 MyApp[7799:1892597] [UE4] Combined iOS Commandline: ../../../MyApp/MyApp.uproject  /Game/PuzzleBP/Maps/PuzzleExampleMap -Messaging -SessionId=EEE054D32B41793D41D525B8C30F7951 -SessionOwner="uerceg" -SessionName="Launch On Device"   -filehostip=192.168.86.33+127.0.0.1  /Users/uerceg/Projects/Unreal/MyApp/MyApp.uproject -RunConfig=
========= This app is in LANDSCAPE mode
2020-12-22 22:12:11.369263+0100 MyApp[7799:1892809] [UE4] Project file not found: ../../../MyApp/MyApp.uproject

From where xcodeproj file is located, I am pretty sure that …/…/…/MyApp/MyApp.uproject exists exactly on that path. And for some reason error says that it can’t find project file in there.

Has anyone encountered similar issue and any advice how to solve it?

Thanks in advance.

2

Having the same problem after a lot of working launches suddenly it brought me this…
Also packaging for shipping works fine

3

the same problem 4.25.4。only being Editor lauched on a ios devoce is ok

4

@amirixx69

5

Were you able to find the solution to your problem?
Iam having the same issue with UE 4.26 and even UE 5.1.
I see a splash screen and then an empty black screen. Nothing else.
I was able to launch from Xcode project and got the same logs as yours that uecommandline.txt Not Found ! etc…

Please help if you have found the solution???

6

Hello
I am facing the same problem. Did u happen to find the solution?

7

Same here with 5.4

8

Same here with 5.4 and Xcode 16.

9

yeah it show up something like this

[UE] Checking for command line in /private/var/containers/Bundle/Application/56FF8D13-2120-492E-B8D2-CBC9A73DD2FE/MyProject.app/uecommandline.txt… NOT FOUND!