Have you tried to go back to an earlier save? That should help. But we'll see for ourselves what the problem is and write about the results here.
i would love to try but im the type of player to play on one save which is kinda what im regretting.
Update i kinda got close to the vault i had to keep saving every time i tried to get the close to it cuz i thought it would be less loading time for the game and it wont have to do as much but i just got to the building thats in the botom left of it and when i try going to anywhere close to the vault the game would crash.