@milanlaia It's possible the windows themselves are broken in some way. If that's the case, you'll need to update or replace the items.
If you'd like to test the windows, you can do so in a clean user folder. Move the entire Sims 4 folder out of Documents\Electronic Arts and onto your desktop, launch the game to spawn a new folder, enable mods and cc, and quit. Then move the files for these windows, but nothing else, to the new folder, and see whether they're rendered properly.
If their textures are still missing, and you can't find updated versions of the items, you can still try redownloading the current versions—it's possible one of the necessary files became corrupted. You can also try changing your graphics settings; maybe a higher or lower lighting or object detail setting will help.
If none of this makes a difference though, there's not much you can do.