Fallout 4 — How to Fix "Crash on startup"
What causes the Crash on startup error in Fallout 4, and the fixes in the order that works.
Last updated 2026-09-25 · evergreen reference
The "Crash on startup" failure in Fallout 4 has a specific cause, and knowing it saves you from working through a dozen unrelated fixes. This page covers what the error actually looks like, why it happens, and the fixes ranked by how often they work.
What the error looks like
Confirm you are dealing with the same failure.
Recognising "Crash on startup"
Fallout 4 closes before reaching the main menu, or crashes at the menu with no error message.
Why it happens
The cause determines the fix.
Cause 1
Mod incompatibility after the next-gen update, which invalidated a large number of previously stable mods — not all have been patched since.
Cause 2
A load order problem: a missing master file, or a corrupted texture being loaded at startup.
Cause 3
Missing Visual C++ or legacy DirectX components, which produces launch crashes before the menu appears.
Cause 4
On modern NVIDIA hardware, certain effects settings interact badly with PhysX-based simulation.
Fixes, in the order that works
Cheapest and most reversible first.
Disable all mods and test vanilla
Use the launcher or your mod manager to disable everything. If the game starts, re-enable one at a time, testing after each. The last one enabled before the crash returns is the culprit — update it, find a compatibility patch, or drop it.
Turn Weapon Debris off
Weapon Debris uses NVIDIA PhysX particle simulation and is associated with crashes on many modern GeForce systems. It is the highest-value stability change in the graphics menu.
Install both Visual C++ architectures and legacy DirectX
Visual C++ 2015-2022 in both x64 and x86 from Microsoft, plus the DirectX End-User Runtime Web Installer for the DirectX 9 and 11 components Fallout 4 depends on. Restart afterwards.
Cap the frame rate to 60
Fallout 4’s physics is tied to frame rate, and startup instability on high-refresh displays is common. Use the NVIDIA or AMD control panel to set a 60 FPS cap for Fallout4.exe, or install the High FPS Physics Fix mod for higher targets.
Check for broken PreVis data
If you see flickering objects or buildings disappearing alongside the crashes, set bPreCulledObjectsEnabled=0 and bUseCombinedObjects=0 in Fallout4.ini to confirm a PreCombine problem, then fix your load order so Boston FPS Fix or PRP loads after the Unofficial Patch but before worldspace mods.
How to confirm it is fixed
One successful launch is not proof.
Retest properly
Start a new game as well as loading an existing save. Crashes that only affect one save point at a corrupted save rather than the installation.
If none of this works
What to do after the list is exhausted.
Gather evidence before asking
Collect your crash log, a DxDiag and the list of fixes you already tried. For Fallout 4, support will ask for all three, and a report with evidence gets a far better response than "it crashes".
Reinstall last, not first
A reinstall is the most time-consuming fix and repairs the same files that verification and cache repair handle in minutes. Try it only after the targeted fixes above have failed.
Related pages
This is an independent player reference and is not official documentation for Fallout 4. GameRulePro does not host or link to copyrighted assets. Modding guidance is for single-player use only — never use mods in online multiplayer. Verify current requirements, prices and policies with the publisher before acting.
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