Thanks Bigtimemaster!
Turning off Lumen worked.
In case someone has the same problem, here’s what I did.
I asked Google BARD how to turn off Lumen :
To turn off Lumen in Unreal Engine 5, follow these steps:
- Open your project in Unreal Engine 5.
- Go to Edit > Project Settings .
- In the Project Settings window, go to Engine > Rendering .
- Under Global Illumination , select Ray Traced Global Illumination instead of Lumen Global Illumination .
- Under Reflections , select Screen Space Reflections instead of Lumen Reflections .
- Click Save to apply your changes.
End of BARD’s instructions.
You can stop at step four. When I clicked off Lumen under Global Illumination, the message disappeared instantly.
(BTW, there is no Save to apply changes; that’s just BARD being silly. )
Of course, now I’m wondering what Lumen is good for and when I’ll need it. But that’ll be the next step I guess.