In a project our studio is working on we have a Slate Postbuffer set up, that mirrors the setup of the VHS scan, and the issue can be replicated accurately using the content examples project.
When opening the map called UI/UI_SlatePostBuffer and playing in editor, approaching the VHS Distortion sample will cover the entire screen in the VHS effect, the effect is opaque and no part of the map can be seen behind it, despite the scene still working as normal (You can move away from the trigger to disable the effect)
Its worth noting, the project we’re working on has this same Slate Postbuffer working on various consoles, and desktop, it seems to only break in this specific way on MacOS.
Is there a specific setup process I have missed or something specific to MacOS that I may not yet be aware of?
I have attached the visuals seen of this effect to this post.
Hardware:
Mac Studio 2025
Chip: Apple M4 Max
macOS: Tahoe 26.3
Unreal Details
Mac Metal Desktop Renderer Beta (SM6, Metal 3.0+): Enabled
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Steps to Reproduce
On MacOS, using the Epic Games Content Examples project on a fresh install of UE 5.6.1 from launcher.
Open Map UI/UI_SlatePostBuffer
Play in Editor
Approach the VHS Distortion sample in the map
Trigger the sample
Observe that the VHS effect fills the viewport completely with no other elements of the scene visible.
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Hi Heinrich,
I’ve loaded up the project on both source and launcher version of Vanilla UE 5.6 on both M3 Max and M5 Max Macbooks running Tahoe 26.5 without issue. Can you confirm that you are using the //UE5/Release-5.6 branch? Additionally can you confirm Xcode version?
[Image Removed]Best regards
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Hi Stéphane,
I can confirm that this issue happens for me on the launcher version of Vanilla UE 5.6.
I’m currently running XCode 16.1
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Hi Heinrich,
Apologies for the tardy response. Epic Games is on Summer break currently but I didn’t want to leave the issue hanging. Based on Xcode version and the fact that you are running Vanilla launcher, this may be caused by the Metal Toolchain attached to Xcode 16.1. Can you try moving to Xcode 26.1 + and let us know if the issue persists? It is worth noting that as of April 2026, Xcode 26 is now required for distribution on the Apple ecosystem.
Best regards.
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Hi Stéphane,
I have subsequently found the cause of this issue, as it turns out the Slate Post Buffer does work with default settings on a clean install, my previous version was using the SM6 Desktop renderer for Mac, and it seems like SM6 is the issue here, going back to the SM5 renderer solves the issue both in the sample and in the game.
I believe that my project was configured for SM6 and when removing and reinstalling the sample it likely just kept the same configuration so even my “clean” run was using SM6
Thank you for all of your effort in assisting me.
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Hi Heinrich,
That is interesting. On this end, I was running the sample against SM6/Metal 3.0+ without issue on Xcode 26.5. It may be worth revisiting if/when you move from Xcode 16.1 to 26.1+.
Best regards.
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