A small Lua-scriptable runtime binary patcher for Windows games. Ships with a curated set of fixes for Deep Rock Galactic.

Compatible with mint, the third-party DRG mod manager. mint and bitfix coexist; you can run both.

Install or update

1. Download bitfix.zip.
2. Find the folder containing the game's .exe. For Deep Rock Galactic on Steam:
   • Right-click DRG in Steam, Manage > Browse local files
   • Open FSD\Binaries\Win64\. You should see FSD-Win64-Shipping.exe in there.
   • On a default Windows + Steam setup this folder is C:\Program Files (x86)\Steam\steamapps\common\Deep Rock Galactic\FSD\Binaries\Win64\.
3. Extract everything from the zip into that folder, replacing existing files when prompted. Keep the window open.
4. Launch the game. Crash fixes apply automatically.
5. Check that bitfix.cfg file and a bitfix.txt log are created next to the game .exe on first launch. If not, please double check you followed the steps and let me know. If using Linux, see the section below.

Don't drop the files in the top-level Deep Rock Galactic\ folder. That folder also contains an FSD.exe (a small launcher), but bitfix has to sit next to the real game executable at FSD\Binaries\Win64\FSD-Win64-Shipping.exe. If bitfix.txt never appears after launching, you probably installed one level too high.

Updating is the same process — download the latest zip and extract over the top. Your bitfix.cfg toggles are preserved.

Linux / Proton / Steam Deck

Install the files exactly as above, then add one extra step: Proton won't load the files unless you tell it to. If the game launches but no bitfix.cfg or bitfix.txt shows up, this is why.

In Steam, right-click Deep Rock Galactic > Properties > General > Launch Options and paste one of these in:

bitfix only:

WINEDLLOVERRIDES="winmm=n,b" %command%

bitfix and mint together:

WINEDLLOVERRIDES="winmm=n,b;x3daudio1_7=n,b" %command%

Then launch the game. bitfix.cfg and bitfix.txt should show up next to the game .exe like normal. You should only need to do this once.

Uninstall

Delete winmm.dll and the fixes/ folder from your game folder. The game goes back to vanilla. You can also delete bitfix.cfg and bitfix.txt if you want a clean wipe.

Enabling and disabling fixes

The first time you launch the game after installing, bitfix creates a bitfix.cfg file next to the game .exe. Open it in Notepad. It will look something like:

# === Crash Fixes ===
drg_csg_arena_bump                        = true   # [client-side] Add +2 GiB of reserved VA to every FSDVirtualMem arena...
drg_expanding_array_uncap                 = true   # [client-side] Dead-code the hardcoded MAXSIZE check...
drg_gc_poison_ref_skip                    = true   # [client-side] GC skips permanent references and rejects observed null, low-address, sign-set, or misaligned poison...
increased_players_crash_fix               = true   # [host-side] Fix crash when >8 players in lobby...
increased_players_difficulty_scaling_fix  = true   # [host-side] Allow difficulty scaling beyond 4 players...
increased_players_mission_end_crash_fix   = true   # [host-side] Fix crash at mission end when >8 players in lobby...
# === Gameplay ===
max_attackers                = false  # [host-side] Raise simultaneous-attacker cap to 200
no_scatter                   = false  # [host-side] Prevent explosions from scattering minerals
non_flare_devouring_drop_pod = false  # [host-side] Stop the drop pod from eating flares
stickier_flame               = false  # [host-side] Sticky flames stick to any actor, not just terrain
# === Visual ===
normal_terrain_scanner_mat = false  # [client-side] Show normal terrain on the scanner instead of scanner material

Flip false to true for any fix you want, save the file, then launch the game.

Role tags tell you when a fix actually does something:

• [host-side] only takes effect on the host's machine. Turning one on while you join someone else's lobby is harmless but does nothing.
• [client-side] takes effect on your local machine regardless of who hosts.

Crash fixes are on by default. Everything else is off.

Will this slow down my game?

No measurable in-game impact. bitfix does all of its work once while the game is starting up. It scans the game binary for the patterns of each enabled fix, writes a few bytes per match, and is done. There's no hook, no callback, and no Lua running during gameplay; the patches are just static byte changes to the binary in memory.

Startup adds maybe a second or two while the pattern scan runs. That's it.

Something broken?

1. Check bitfix.txt next to the game .exe. It logs every loaded fix, every pattern match, and any errors.
2. If a fix's pattern didn't match the current game build, you'll see no pattern match for <fix>/<label> in the log. Disable that fix in bitfix.cfg and report it.
3. To rule out bitfix entirely, delete winmm.dll from the game folder and launch.

Catching new crashes

When a fresh crash shows up that nobody has a fix for yet, the most useful thing you can do is collect a full crash dump and share it.

To enable full dumps:

1. In Steam, right-click Deep Rock Galactic > Properties.
2. Under General > Launch Options, add: -fullcrashdumpalways
3. Close Properties. The next time the game crashes, a full dump is written automatically.

To find the dump:

1. Right-click DRG in Steam, Manage > Browse local files.
2. Open FSD\Saved\Crashes\. On a default Windows + Steam setup this is C:\Program Files (x86)\Steam\steamapps\common\Deep Rock Galactic\FSD\Saved\Crashes\.
3. Each crash is its own timestamped subfolder containing the dump (.dmp), a log, and metadata. Zip up the whole subfolder if you want to share.

Warning: full dumps are large. Each one is typically 2-5 GB and they pile up fast. Clear the Crashes\ folder periodically, or remove -fullcrashdumpalways from launch options once you've captured what you need. Without that flag, the game writes much smaller minidumps that often miss the data you'd need to diagnose a new crash.

For developers

See DEVELOPING.md for how to write your own fixes and build from source.

License

MIT. See LICENSE.