The material "M_Volumetric_Sky_Prototype" has numerous compile errors that prevent it from being used.
This was reported and tested in 4.25 Preview 2 (CL-12055273) and reproduced in 4.26 (CL-12192349)
Results: Numerous compile errors on the Material preventing it from rendering
Expected: The material is rendered and has no compilation errors
There's no existing public thread on this issue, so head over toAnswerHub just mention UE-90771 in the post.