Yep! I duplicated most of the required items and placed it in the barracks, but when I got to the last duplicated screws it kept saying “Syncronization error. Restart the game.” I proceeded to do so multiple times and still got the same message. I had a suspicion it was because of the screws, and seeing your answer really helped solve this headache of mine. I can’t buy anything in the in-game store anyways (keeps saying “error connection” something and everything costs £100), so will grind for the rest of the screws. Thankfully, I got 8 out of the 10 screws required, so just need to farm motel one last time before I can complete the barracks.
However, thanks for clarifying it for me, bro! Otherwise, I would have kept stressing over this. It was pretty frustrating, so I really appreciate your help. So, thanks again!