I feel like this is a weird problem to have, but, well, I have it.
Every time I try to leave the Strip/Freeside, whether by fast travel or going through the door, I get instantly killed. No reaction time, no loading, just an instant headshot and then the game reloads to my last save. Now I know there aren't enemies with really excellent aim just waiting wherever I go (it doesn't matter which fast travel point I use), so it must be an issue with the game.
This has happened at various other points during the game, but could be fixed by loading an earlier save and going in and out of a building. It's happened with no mods, and it's happened while using a bunch of mods. This time, however, it doesn't seem to be fixed by anything I do.
Has anyone else had this issue? If so, what did you do to fix it? Right now, it's making the game unplayable, because I can't leave the Strip/Freeside area.