Missing side of the meshes

I have several problems with this pack:

Some side of the meshes are missing textures or are invisible:

Imgur

Imgur

Did I miss something ? I’m sorry if this is a dumb question, but I can’t find the solution anymore on the forum.

Thanks in advance

it looks to me like your normals got flipped. if thats the case then you can try reimporting the assets or you may need to take them into a outside program like may max or blender to adjust the normals. to check the normals in ue4 just double click the mesh to open it then click the button at the top which says normals. this will give you a visual representation of the normals direction, it should be some green lines that protrude from the face/verticies of the mesh.

also you already posted this question at the below link

Hello, Thanks for your answer, you can see here what I got:

Sorry but i’m really new with this software. What does it mean ? Are the green lines showing something wrong on this picture ?

I try to use the option “double sided geometry” on the meshe or “Two Sided” on the material but it doesn’t work.

from what i can see that one in the picture your normals looks ok in that one.

What does it mean ?

what does what mean?

“double sided geometry” not sure on that one. ““Two Sided” on the material” in this particular case its better to fix the underlying issue rather than use that option. two sided material is so you can see both sides of a single plane which is useful for things like plants which need to be thin, in your case however you wont be seeing the faces from the backside so theres no need to have them show materials it would be a waste. when i say backside in this case i mean from the inside of the mesh, think the area that would be solid in real life.