DX12 and/or Ray Tracing causes editor to crash when opening a new viewport/material/mesh viewer

I’ve been trying to use UE 4.22 with Ray tracing turned on for a few days but every time I open the project it crashes when I open a new window/tab with a render preview window in it, the editor locks up completely.

This doesn’t happen in 4.22 projects that don’t use the -dx12 start line.

When I use DX12 I see an error in the log repeated saying:

LogD3D12RHI: Display: Root signature created where the root parameters take up 18 DWORDS. Using more than 12 DWORDs can negatively impact performance depending on the hardware and root parameter usage.

The editor doesn’t seem to lock up when I’m just running DX12 but when I turn on Ray Tracing and try to open a material to edit or something similar it locks up.

From what I can see the Ray tracing is working fine in the viewport. I can see the reflections and I can see the GI or AO updating if I move the camera, but if I open another tab with a render window it locks up immediately.

Does anyone have any ideas whats going wrong?

I have the same problem
RTX 2060


I have exactly the same problem. After a few seconds the motor closes with that error.

Is there a chance that its a similar issue?

Try opening the editor on an extra monitor if you are on a laptop.

And also this is what I posted on another topic

"Ok, I finally found a workaround, which is not the best but at least it lets you to work on any project if you dont have a monitor around.

Normally if you disable intel card from device manager before opening ue4, the engine doesnt work, but if you open the project with the intel card enabled and as soon as engine starts you should minimize the engine without clicking anything, its important that you minimize it, otherwise the video card crashes, then after minimizing go to the device manager and disable the intel card, then the editor should work."

Another workaround is enabling editor debugging symbols, but it crashes large projects.

I have the same problem with gtx 1080ti. Driver nvidia= 430.64

I’ve got a bug report! Vote for it if you’re still having this issue guys, projected fix is 4.22.2!

I had exactly the same error, try to find some solution and it was very complicated, epic already knows about the error and according to a thread probably solve it in version 4.23

I have version 4.22.3 and 4.23 preview and recently I started having that error when starting a project on anyone using DXR.

Rtx2080 oc
Amd Ryzen7 2700x

After seeing in many forums and trying all the supposed solutions, I found something simple that finally fix my problem.

I entered the Nvidia Geforce Xperience panel and in the graphics update screen (top left) in the option “Choose your driver preference” eleji driver for study, I updated the drivers cleanly.

Then I started the engine and that’s it, I have not had that mistake again, I hope it helps.

Just a quick note - 1080ti’s are not RTX gpus, so by default they cannot do ray-tracing in UE4 (as it is hardware based, not software based).