Fixing the 'Fatal Error' in Quarantine Zone: The Last Check
If you’ve been playing Quarantine Zone: The Last Check, you’ve likely encountered the game’s most notorious adversary: a random freeze accompanied by a simple, unhelpful “Fatal Error” message.
This crash can strike at any time, but it becomes particularly prevalent around Day 19 when the Ultra Violet scan is introduced. I discovered that the issue stems from how the game handles process priority and CPU threading. By restricting the affinity to physical cores (skipping virtual/logical threads), we prevent the threading conflicts causing the engine to hang.
The Solution: Intelligent Affinity and Priority
Forcing the game to use only physical cores and elevating its priority class completely eliminates the Fatal Error. I have created a universal automation script that handles this entire process for you.
Note: This is not a permanent one-time patch. Because the game resets its CPU affinity on every launch, you must run this script every time you want to play to ensure the fix is applied.
🚀 Universal Anti-Crash Script
The script below is designed to be completely automatic. When run, it will:
- Probe your CPU for physical core count.
- Match your hardware to a pre-calculated optimal affinity mask.
- Launch the game via Steam.
- Wait and Persist: It continues to check the game for 15 seconds after launch to ensure the settings “stick” even if the game engine tries to override them.
The Automation Script
Copy the code below or use the download button. This script must be Run as Administrator.
Click to view/copy script source code
@echo off
setlocal enabledelayedexpansion
REM ================================================
REM Quarantine Zone: The Last Check - Anti-Crash Fix
REM ================================================
set PROCESS_NAME=QZSim-Win64-Shipping
set STEAM_APP_ID=3419520
echo ================================================
echo Game Launcher with Hardware Profile Detection
echo ================================================
echo Game: %PROCESS_NAME%.exe
echo Steam App ID: %STEAM_APP_ID%
echo ================================================
echo.
REM Probe hardware for physical cores
for /f "tokens=2 delims==" %%a in ('wmic cpu get NumberOfCores /value ^| find "="') do set CORES=%%a
set CORES=%CORES: =%
echo Detected %CORES% Physical Cores.
REM Match hardware to pre-calculated masks (Alternate Cores 0,2,4...)
if "%CORES%"=="4" (
set MASK=85
set LIST=0,2,4,6
) else if "%CORES%"=="6" (
set MASK=1365
set LIST=0,2,4,6,8,10
) else if "%CORES%"=="8" (
set MASK=21845
set LIST=0,2,4,6,8,10,12,14
) else if "%CORES%"=="10" (
set MASK=349525
set LIST=0,2,4,6,8,10,12,14,16,18
) else if "%CORES%"=="12" (
set MASK=5592405
set LIST=0,2,4,6,8,10,12,14,16,18,20,22
) else (
echo [!] Unknown core count. Defaulting to 6-core profile.
set MASK=1365
set LIST=0,2,4,6,8,10
)
echo Selected Mask: %MASK% (Cores: %LIST%)
echo.
REM Launch the game via Steam
echo Launching game...
start steam://rungameid/%STEAM_APP_ID%
echo.
set /a COUNTER=0
set /a MAX_WAIT=30
:WAIT_LOOP
tasklist /FI "IMAGENAME eq %PROCESS_NAME%.exe" 2>NUL | find /I /N "%PROCESS_NAME%.exe">NUL
if "%ERRORLEVEL%"=="0" goto FOUND_PROCESS
set /a COUNTER+=1
if %COUNTER% geq %MAX_WAIT% (
echo [ERROR] Timeout: Process did not start within 60 seconds.
pause
exit /b 1
)
timeout /t 2 /nobreak >nul
goto WAIT_LOOP
:FOUND_PROCESS
echo Process detected! Applying persistence loop...
REM Persistent setting loop (forces settings every 3 seconds for 15 seconds)
REM This circumvents the game engine trying to override affinity during load.
set /a LOOP_COUNT=0
:PERSIST_LOOP
powershell -NoProfile -Command " = Get-Process -Name '%PROCESS_NAME%' -ErrorAction SilentlyContinue; if ($p) { try { $p.PriorityClass = 'High'; $p.ProcessorAffinity = %MASK%; } catch {} }"
set /a LOOP_COUNT+=1
if %LOOP_COUNT% LSS 6 (
timeout /t 3 /nobreak >nul
goto PERSIST_LOOP
)
echo.
echo ================================================
echo SUCCESS! Optimization Finalized.
echo ================================================
timeout /t 5 /nobreak >nul
exit /b 0Unlimited Experiences - Solving one Fatal Error at a time.