Why is creating a new layer destroying my landscape?

[SupportiveEntity]

Hey there @MajekPL! It looks like the landscape shader needs to be rebuilt or has a sampler issue. Here’s a reference to a post that had a similar problem with a couple of solutions:

SOLVED: Grass maps need to be rebuilt?

SOLVED: “From the looks of it, you might want to try selecting your Texture Samples within your landscape’s material and set the Sampler Source to Shared:Wrapped to see if that resolves your issue.”