Particles are weird and can disappear by themselves, especially if you mess with slow motion and stuff, they will come back after restarting the game. I don't think a mod is causing it because they are handled by game engine which is not accessible for modders. Unless a mod messed with your settings and set them so low that the particles got disabled.
i have tried to restart the game and even when i reinstall the game it still doesnt work --- Post updated --- it also works without mods and doesnt work with mods --- Post updated --- nevermind it turns out that the mod that was breaking it was a map called setlvio pass
