" The non-cinematic texture is very large. It's 3840x2160. Use LODBias to reduce its size to 2,048 or less. (FortValidator_Textures) "

Hello Gatito,

Open the texture and try increasing the LOD Bias in your texture. (Try ‘2’)

If that does not work, reduce the resolution of your texture. (2048 max in a dimension) and re-import.