Mac OSX Shader compiling crash

I am running OS X 10.11.6
Opening material editor crashes the editor after waiting a few seconds. The same crash occurs when building lighting. The crash reports are identical Crash Log

Hey Dr. Steak,

Can you provide more information about when this crash occurs so that we can try to reproduce the issue on our end? For instance, does this occur in a blank Blueprint project or only your custom project?
Also, please provide as many of the following as possible:

  1. Your Mac’s specs. You can find this in the Apple menu >About This Mac>More Info> Add the information from this window (serial # not necessary).
  2. The “System Report:” Apple menu >About This Mac > System Report>Hardware (All information listed in the “Hardware Overview.”) You can cut and paste this information or provide screen shots, whichever is more convenient.
  3. The UE4.log (Located: ~/Library/Logs/Unreal Engine/Editor/)
  4. The ProjectName.log (Located: ~/Library/Logs/Unreal Engine/ProjectNameEditor/)
  5. Please be sure to hit “Submit” on the Crash Reporter pop-up to send the Crash Report to Epic so we can compare this to other relative data.

Providing this information and appropriate logs will help us track down and isolate the source of the bug as quickly and efficiently as possible.

Thanks for your cooperation,


It occurs on every project, even blank projects. I suspect it might have something to do with me having the engine installed in another drive and then using symlink to redirect the launcher. But anyway here are my specs:

  • 3,7 GHz Intel Core i3
  • 8 GB 1600 MHz DDR3
  • NVIDIA GeForce GTX 750 Ti 2047

Hardware Overview:

  • Model Name: Mac Pro (Not actually Mac Pro, it is custom built)
  • Model Identifier: MacPro3,1
  • Processor Name: Intel Core i3
  • Processor Speed: 3,7 GHz
  • Number of Processors: 1
  • Total Number of Cores: 2
  • L2 Cache (per Core): 256 KB
  • L3 Cache: 3 MB
  • Memory: 8 GB
  • Bus Speed: 400 MHz
  • Boot ROM Version: MP31.006C.B05
  • SMC Version (system): 1.25f4
  • Serial Number (processor tray): CK929NQ4XYL2BC3A2
  • Hardware UUID: BE0BFCBA-977C-5EB3-9CB8-567D8408CF68

Reproducing the crash might be hard, but here are the steps anyway

  1. Create blank project
  2. Create material asset/Build lighting
  3. Wait for about 30 seconds (if you decided to create material)
  4. Crash

If they don’t work then it might be worth trying to:

  1. Install engine 4.13
  2. goto /Users/Shared
  3. move the UnrealEngine folder to another drive
  4. Create symlink by
    ln -s /pathToUEFolderInAnotherDrive/ /Users/Shared/UnrealEngine
  5. Restart launcher
  6. Launch UE4
  7. Repeat steps 1-4 at the beginning of this comment

We were not able to reproduce this by launching UE4.13 from an external drive via symlink as you describe above. Please launch the editor from the .exe file: UnrealEngine>4.13>Engine>Binaries>Mac>

If you are still experiencing the issue when launching the editor this way, then the issue is not related to the editor being set up as a symbolic link.

That fixed it! The editor isn’t crashing now that I launched it directly from the .app. Material editor and lighting building work now.

I also noticed in the material editor that when you create a material asset the preview mesh that shows the material looks like

and after waiting for a few seconds it turns into

. That is the moment it would crash when the engine was launched from the Epic Games Launcher.

Well I’ll just use the for now. Thanks for help!

Hi Dr. Steak,

I’m glad to hear that the workaround is working for you, however, using your repro steps we were able to reproduce the crash and have entered the following bug report: UE-38485.

You can follow this issue on the following link:

Unreal Engine Issues

Thanks for bringing this bug to our attention,