5.8 Freezing on UI interaction

General Issues and Bug Reporting (Unreal Engine)
1

Summary

Following issues not present in 5.7.4: Upon load, buttons or dropdown menus cause complete freeze and sometimes crash. For some reason i can load the new project window and mouse around, but selecting a dropdown or hitting the create button will freeze 100%. Have also tried loading with these flags SDL_VIDEODRIVER=x11 ./UnrealEditor -dx11. This was repeated with a ubuntu 22.03 docker, but this version is outdated and doesnt support newer radeon cards, so UE 5.8 wont load.

System:
Ubuntu 24.04
XFCE X11
Ryzen 9 5900xt
Radeon R9700 (RDNA 4)
64GB DDR4
AM4 socket

What Type of Bug are you experiencing?

Editor

Steps to Reproduce

Run 5.8 on an ubuntu X11 DE. If it works try it with a radeon card (rdna 4 with latest mesa driver).

Expected Result

The UI of UE can be navigated without freezing.

Observed Result

The UI of UE freezes.

Affects Versions

5.8

Platform(s)

Linux

[UE 5.8][DX12] Editor hard-freezes at EndDrawingViewport/Slate on RX 9070 XT (regression from 5.6)
Vulkan RHI submits batches that wait on binary semaphores before the corresponding signal operations are submitted (violates VUID-vkQueueSubmit-pWaitSemaphores-03238); deadlocks on Mesa/RADV Linux
2

Love how the release notes list linux support when it not even working on a “supported” distro like Ubuntu

2 Likes
3

Also same issue sadly.

4

Another bug report I saw.. Expected result “Work” pfft..
Sad but that’s basically the crux of it.

5

I upgraded from a source build of 5.7 release to 5.8 release and the editor freezes shortly after launch.

By default, the editor loads as a giant black screen with white lines.

If you run with the following Env vars:


SDL_VIDEODRIVER=x11
RADV_DEBUG=hang

and the following renderer settings:

[/Script/Engine.RendererSettings]
r.RayTracing=False
r.DynamicGlobalIlluminationMethod=0
r.Shadow.Virtual.Enable=0
r.ReflectionMethod=0

The editor will launch for me but freeze up after a few seconds.

Quite frustrating.

6

(post deleted by author)

7

Hello, I managed to fix UE 5.8 black screen/crash on AMD graphs cards and the constant freezing that happens when using UE 5.7 or UE 5.8.

I created 2 MRs on Mesa to accomplish this fix:
MR1 black-screen/crash: Making sure you're not a bot!
MR2 freezes: Making sure you're not a bot!

I created a stacked branch because AMD users needs both MRs to UE 5.8 be usable.

you will need the packages to build it

ninja
meson
python-mako
python-yaml
python-packaging

meson setup build . \
    -Dgallium-drivers= -Dvulkan-drivers=amd -Dllvm=disabled \
    -Dplatforms=x11,wayland -Dbuildtype=debugoptimized -Dbuild-tests=true \
    -Dprefix="$HOME/.local/mesa-radv-test"

ninja -C build
meson test -C build
meson install -C build >/dev/null

echo "Installed: VK_DRIVER_FILES=$HOME/.local/mesa-radv-test/share/vulkan/icd.d/radeon_icd.x86_64.json"

then you can run UE with your new compiled mesa

VK_DRIVER_FILES="$HOME/.local/mesa-radv-test/share/vulkan/icd.d/radeon_icd.x86_64.json" SDL_VIDEODRIVER=x11 /opt/unreal-engine/Engine/Binaries/Linux/UnrealEditor

Hope Mesa devs review those MRs and it gets merged/fixed to everyone.

1 Like
My Experience Unreal Engine 5.8.0 Preview on Linux
8

Hi @bertonha I saw your comment in my ticket: Making sure you're not a bot!

I will compile your stacked-fix branch and test it on my RX 7700 XT (RDNA 3) / Kubuntu setup, then give you feedback on whether it resolves both the crash and the freezes.

Thank you for working on this! Have a nice day.

9

Hi @bertonha I finally had some time to try your fix and hey it works. I can’t believe it. To be honest it was difficult to find all missing dependencies for building it, but It works.

There is no crash, no black screen no memory leak in one hour of testing. I had memory leak in 5.61 Solution was: r.Vulkan.AllowSplitBarriers 0 command.

Thank you for resolving this issue.