strange growing black growth artifact in viewport [only in lighting and detailed lighting modes]

Hi As it says really.…ibLA0qhha?dl=0

images here to show what im experiencing. Just had an RTX replaced because I was getting system freezes and this as a visible symptom. No system lockups yet but still this weird artefact exists that grows until it fills the background. If iI move the camera/navigate again in a different direction it will start again, small at first but then grows out again. It doesn’t encroach on the foreground geometry ever [which in my scene is a car and a ground plane] and there or no sky spheres are other dome like static meshes surrounding the scene [even though the effect of the artifact growth makes it look like it does].

any ideas anyone?

Using the latest Studio Driver 442.19 release 02/03/20
In Nvidia Control Panel>3d Settings> Global & Program [UE4] power management mode ‘prefer maximum performance’
Ue4 preview 4.2504 but also occured on 4.24.1



had an rtx card replaced by the supplier as they thought it was a card issue as have Nvidia …
anyone using the software or @epicgames who can help with this?


Does it appear in every scene? If you start a new project and open the Minimal Default map, for example, is it still there?

thanks for getting back!
It only seems to appear in Detailed Lighting and Lighting Only view modes in my current rtx project.
Created a Blank Project template with raytrace enabled and the artefact does not appear in either modes…So i have a project specific issue it seems…:wink:

Should have checked that really.;/
I attach a screenshot of my world outliner showing what is in the scene…