After some investigation, I found (so far) that game optimized poorly and mostly crashes on PC with NVIDIA graphics cards and Windows 10/11. Windows 10/11 works different with memory and it cause to accessing to some memory addresses that crashes game. Most of known solutions don't fix the problem completely. Reducing zombies count, entities (physical, movable), particle emitters or models variety also does not fix the problem.

Not effective:

• Using VM with Windows 10 x32 bit
  
• Increasing pagefile
  
• Changing HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\DisablePagingExecutive from 0 to 1

Noticed: Highest chance to get crash when you loaded one game and trying to start another one after it. Game doesn't do any cleanup in memory so it crashes the game.
Second one - starting new game when world has base and chunk Firehall_Boutique

So we have 2 options:

• Try to reduce crashes on Windows 10\11
  
• Use Windows 7 to run game

• PhysX 9.09.0814[drive.google.com] <- any version is okay but not legacy
  
• XNA Framework 3.0[drive.google.com]
  
• .Net Framework 3.5[drive.google.com]

Download here: https://drive.google.com/drive/folders/15ejMh1ynrmnaj2Nmus5vLAAyBT90loYG

Thanks to all guys who tested and mentioned about this options.

Old:

Open NVIDIA Control Panel.
Go to Manage 3D Settings > Program Settings > Select a program (fortzombie.exe) > Select the preferred graphics processor (Integrated graphics)
Go to Configure Surround, PhysX > PhysX Settings > Processor (CPU)

1. Apply 4GB patch[drive.google.com] to fortzombie.exe
2. Use Windows 7 Compability mode for fortzombie.exe

1. Apply small fix[drive.google.com] and start autopatch.bat (follow instructions)
2. Run game with arguments XenParticlesEnabled=false ScreenWidth=1080 ScreenHeight=720
3. Reduce video settings in game (try lower as possible)

Okay, that can be possible due to these videos

1. Install VMware Workstation Pro[drive.google.com] (VirtualBox is weaker for gaming)
2. Make Windows 7 (ultimate or enterprise edition) virtual machine
3. Set maximum of your videocard's capacity + 3D acceleration, 8+ GB RAM
4. Install VxKex and Legacy Update (from videos above)
5. Install Steam, redistributable stuff[drive.google.com], FZ
6. Run game from directory folder

1. Install VMware Workstation Pro[drive.google.com]
2. Download prepared Windows 7 VM[mega.nz] (~8GB)

If main menu start glitchy -> try to start new game and return back or just make screenshot (press PRT SCR)

Just for in case
Old Steam build from archive: https://archive.org/details/steam-1726604483
Tool to download game: https://github.com/SteamRE/DepotDownloader

• FullScreen=false - windowed mode
  
• ScreenWidth=1080 - width in pixels
  
• ScreenHeight=720 - height in pixels

• Debug=true - enables Debug mode
  
• SessionLog=true - prints data to fzlevelcontentlog.txt (in game folder)
  
• VisualizeAI=true - shows zombie states
  
• ShowPlayerAnimationDiagnostics=true - draws player's animation state + route
  
• ZombiesEnabled=false - disable zombies
  
• SoundEnabled=true
  
• MouseVisible=true
  
• ResetAchievements=true
  
• XenParticlesEnabled=false - dont know
  
• ExtendedDebug=true - dont know
  
• ContentMount= (string) - dont know
  
• EditNavigation=true - dont know
  
• Level= (string) - not working
  
• AudioDir= (string)
  
• SaveGame= (string) - internal error without crashing
  
• AnimationReposePeriod= (double) - not working
  
• DrawDistanceModifier= (float) - not working / 1f by default
  
• IrisSceneType=Normal - dont know

There's couple more but it's not useful

To run it just make shortcut with this params: FortZombie.exe XenParticlesEnabled=false Debug=true SessionLog=true
or you can use FortZombieDebug[drive.google.com] file to run game. Just put it into game folder (near FortZombie.exe) and run it.

Don't press Validate Game Content -> game will crash immediately

You need to enable Debug mode first
This is quite simple menu that allows you to:

• Choose character, daytime, mission type and load specific chunk of map (main scroll). Don't try to load any _navgraph "map" -> game crashes immediately
  
• Choose fast preset (missions)

0. Unpack fz.gob file using 7zip at game folder (you'll get fz.gob folder), remove fz.gob file
1. Download Python 3.12+[www.python.org]
2. Download my XNB XML Editor[drive.google.com]
3. Open CMD in folder with script
4. Write down pip install -r -r.txt and wait till end
5. Write down py xnbeditor.cpython-312.pyc


Open .xnb files from FortZombie/fz.gob/Config
Make backup, edit, save, run game.
Game crashed? Restore from backup

Mod examples:
New Character Class[drive.google.com]

Download: https://drive.google.com/file/d/1dRWZehGjfMSMG7unHk78_WJZHwyVUgvX/view
Link by: @warmowed

It's possible to add (remove or replace as well) elements onto map.
This vending machine will looks like this in file Base_PoliceStation.xnb


Open .xnb files from FortZombie/fz.gob/Levels using same XNB XML Editor[drive.google.com] and edit as you want (unfortunately we don't have other way but only with this configs)

• TerrainModel - static model
  
• Model - model with physics
  
• ZombieWave - zombie spawner
  
• MaskedSpotLight
  
• Light
  
• Container - model with inventory
  
• ParticleEmitter - smoke, fire
  
• MissionBeacon
  
• SurvivorSpawnPoint
  
• BreakableSlab - window glass
  
• HingedDoor
  
• Building - prebuild map
  
• StartPoint - player spawner

It's also possible to change some textures in game
Mod example:
Custom UI Elements[drive.google.com]

Collision view -->
Ctrl + Alt + F2
Reset player position
Ctrl + Alt + F12
Change daytime (skybox, light)
Ctrl + Alt + T
Hide HUD
Ctrl + Alt + H
Run defence mission
Ctrl + Alt + D
Change camera
(free camera, behind shoulder, classic)
Ctrl + Alt + С or V
Spawn survivor
Ctrl + Alt + S
Spawn zombie
Ctrl + Alt + Z
Hide physical models
Ctrl + Alt + End
Noclip mode
Ctrl + Alt + F3
Lift player while noclip -->
Ctrl + Alt + Space
Top view
Ctrl + Alt + PageDown
Close view
Ctrl + Alt + PageUp

Do not use this hotkeys while main menu, game will crash

• Navigate to C:\Users\*username*\AppData\Local\Kerberos_Productions\FortZombie.exe_Url_***\1.0.7.0 (or use FortZombieData[drive.google.com])
  
• Find <RenderQuality> tag and make it as <RenderQuality>VeryHigh</RenderQuality>

Not sure if the quality will be better but it's an official option that not showing in list

I liked robocrush123's idea about FZ speedruns. Thanks to him about it.
And thanks to my guide it's possible now without game crashes.

Leaderboard: https://www.speedrun.com/Fort_Zombie_
WR