A Curious Little Fallout 76 Movement Bug

While I never signed up or declared my intention to take part in Blaugust, on August 1st I got some FOMO and wrote a post. Then another on the 2nd, and another after that and here we are half-way through the month and I’ve kept it up. But my batteries are running down, mostly because half my team at work is on leave or vacation just as the summer lull is ending and projects are starting to heat up. One team member comes back next Tuesday so I THINK if I can get through to then, I might make the full month, but this week has been tough. (Plus GamesCom is next week which should provide plenty of blog fodder.)

All of which is a preamble to a short little post about a curious bug I ran into in the PC/Steam version of Fallout 76. Yes, now I’m playing Fallout 76 on Steam…did I mention that here? First I was going to play it on GeForce Now but then I got hooked (again!) and decided to install it locally.

So I was having a great time of it for a while, then suddenly I lost the ability to move. I was playing with a controller and at first thought it was a controller bug. I would turn and look around a bit and then suddenly I’d start moving again. I figured that was my cue to get used to playing with mouse and keyboard. But the same thing happened even after I’d set the controller aside. It hadn’t happened when I was playing on GeForce Now, though. And I noticed it seemed to happen more when I was in a building than when I was outside. I had installed a mod that was supposed to improve wide-screen support, so I disabled that (honestly I didn’t notice much different anyway…but FO76 could really improve its wide screen support). That didn’t fix the bug. But through continued messing with it I discovered that it mostly happened when I looked down to loot a body, and looking up at the sky would often fix it.

Screenshot of the fallout76prefs.ini file
If you’re playing the Xbox Windows version of Fallout 76, look in Project76Prefs.ini instead

To keep a short post short, it turns out it was a framerate issue. When I looked down at the ground, or when I was inside an enclosed area, the framerate went so high the that game just seemed to freak out and couldn’t keep up or something. THAT was when I remembered that I’d followed YouTuber AngryTurtle’s advice to change a setting in the Fallout76Prefs.ini file. The specific setting was iPresentInterval=1 which we were told to set to iPresentInterval=0 to make the game run much better. Which in fact it does…it apparently turns off the FPS cap and the game’s built in VSYNC. But it maybe does TOO good a job?

The solution is either to just turn that back to 1, or to use the Nvidia control panel to cap the framerate. I did the latter, setting max framerate to 144 fps which is what my monitor runs at. I had a bit of screen tearing when I looked down and ran, so I also turned on Nvidia Vsync. That fixed the issue for me.

It was just such a weird bug that rather than annoy me, I found it kind of amusing and fascinating (OK I mostly felt that way AFTER I solved it). If any devs wander by I’d love to hear a theory as to why too high a framerate would make a game engine just sit down and cry like this!

Screenshot of my nvidia control panel settings for fallout76.exe

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