When i copy something this is only copying the old version of the things?

For example i was copying a script from one of my gun and put it in another gun. Strangely the gun was acting like a old version (no sparks, no bullet hole, no bullet trail). So i go in the script of the first gun, copy the text of the script directly and past it in the other gun script, and wow, its work. Everytime i copy a script its print a old version or just a " Print("Hello world!") ". I noticed other bugs with sounds and part when i copy them, but i dont remenber what they are. I was wanting to post this in the devforum because its more a studio bug but the new topic button never appear.