Does anyone have any idea why this is happening?

Edit: The image won't work but my mountains are missing.

Are the textures replaced with an exclamation point

Missing meshes would cause that, Wog. Not textures.

Tesvixen wrote:

Missing meshes would cause that, Wog.  Not textures.

thanks for telling me I accidentally misread the post.

dasjelly wrote:

Does anyone have any idea why this is happening?

Edit: The image won't work but my mountains are missing.

You might find you are running too many mods because having too many esp's active can mess up your game as I had a similar issue where eye and armour textures would replace walls and the ground plus there it looked like black shapes replace the mountains.

The mountains aren't entirely missing, but there are chunks of them replaced with basically nothing. I only have about 40 ESPs loaded.