I have an interesting problem. I played for about 70 hours without any real problems but now my game exits at the same point about 30 seconds in with the infamous "Falloutnv has stopped working" popup. Since I'm using a dual-core I decided to the "bUseThreadedAI=1" patch on the Fallout.ini file. This doesn't work but I have noticed that if I go back to the Fallout.ini file the line has reverted to "bUseThreadedAI=0" and the other line that I typed in is gone again. In essence, my Fallout.ini file has removed all of my changes??? Anyone have an idea of why this might be?

@Buhler: If you have modified your .ini file, I would suggest resetting it completely. Many of the performance 'tweaks' out there merely reduce the stability of the game, especially ones dealing with memory and cpu threads. I'd try running without any overclock as well, since the game can be fickle about it.

there are two ini files for the game one in the steam folder the other in my documents. My guess like the early auto save issues one is overwriting the other.

Thanks donta1979, but I can only find the one in the my documents folder. Do you have a path for the one in the Steam folder?

It's a fix from Fallout 3 that solved crashing on quad-core CPUs for many people. I believe it just limits the engine to use only the amount of cores you specify. I've been using it on mine limiting it to 2, and it is very stable.

Sorry to hear it didn't work for you though. You can always trying limiting it to 1 core (iNumHWThreads=1) and see how it behaves. In the old tweak guide the author suggested trying 1, 2 and 4 to see how it behaves.

And in regards to the ini, the one you want to edit is /Documents/My Games/FalloutNV/FalloutPrefs.ini

Still no joy I'm afraid. I changed it in the FalloutPrefs.ini and the Fallout.ini and while the two lines stayed in the FalloutPrefs; once again my Fallout.ini reverted back to the original once the game crashed :shrug:

Don't worry about the Fallout.ini, all it seems to be is a read-only copy of the default ini from the main game folder. FalloutPrefs is what the launcher changes and what the game actually uses for it's settings.

Well in that case, it looks like that isn't the answer.

After some playing around, I've confirmed that my game locks every time my NPC Companion (Cassidy) attacks something. When I went solo, it didn't seem to happen. Anyone have an idea what this is all about?

For anyone experiencing the same problem as me (the one in the OP), the solution is to play the game windowed, at least until Bethesda puts out a patch. It also helps a lot with the random crashes, I just played for 3 hours without a crash.