Terrain Texture Changes In A Black Texture

Hi, i’ve set the texture of my terraint but when i’ll return to menu, next i’ll go to that scene the texture of the terrain it’s all more dark and when i’ll stop the game it’s all black . It’s a bug of unity? I’ve used the normal map too.

The question is too vague to answer properly, but one thing that comes to mind if you are modifying the splatmap runtime and ending up with a section that has all textures at that point set to full transparent, resulting in black.