Thanks for answer so soon. sorry for the delay
I had installed a sky mod but uninstalling it fixed the problem. I'm not sure if it had anything to do with it, but it seems that it does because the problem has not returned.
The only mods that I have installed are here in the link that I put you and if I am right one of them created the conflict. I think it was the one that changes the sky.
Steam Community :: Guide :: [ENG] INTRODUCING: MODS! 9 MODS TO IMPROVE YOUR GAME
I had installed a sky mod but uninstalling it fixed the problem. I'm not sure if it had anything to do with it, but it seems that it does because the problem has not returned.
The only mods that I have installed are here in the link that I put you and if I am right one of them created the conflict. I think it was the one that changes the sky.
Steam Community :: Guide :: [ENG] INTRODUCING: MODS! 9 MODS TO IMPROVE YOUR GAME