“Initializing AI Spline” in Assetto Corsa: why the game freezes and how to fix it

you run Assetto Corsa, select a track, press “Drive” - and instead of a race you see an endless loading with the inscription «Initializing AI Spline». Minutes drag on, the game does not respond to keys, and in the worst case, it crashes completely with an error. Is this a familiar situation? This problem has been plaguing gamers since 2014, but its causes and solutions are still shrouded in myths. Unlike typical “lags” in games, freezing at the initialization stage AI Spline associated not so much with iron, but with mod conflicts, damaged track files or incorrect physics settings.

In this article we will look at all current ways to solve the problem for 2026, including little-known tricks for editing configuration files and diagnosing conflicts between plugins. Important: if you use a pirated version of the game or downloaded mods from dubious sources, some methods may not work - we’ll also talk about this below. Don't waste time reinstalling the game (this only helps in 20% of cases) - check our recommendations first.

What is “AI Spline” and why does the game freeze at this stage

AI Spline is an internal mechanism Assetto Corsa, responsible for calculating the movement trajectories of artificial intelligence (bots) on the track. At the stage Initializing AI Spline the game analyzes:

• 📊 Track geometry (turns, elevation changes, curbs)
• 🚗 Car physics parameters (clutch, aerodynamics)
• 🎯 Optimal braking and accelerating points for AI
• 🔄 Dynamic objects (such as moving barriers or changing weather conditions)

Freezing occurs when the game cannot process this data correctly. Most often the culprits are:

1. Damaged route files (especially if you installed custom tracks).
2. Mod conflicts, changing physics or AI (for example, SOL, Content Manager with incompatible plugins).
3. Lack of RAM when loading complex routes (for example, Nürburgring Nordschleife with 150+ bots).
4. Errors in configuration files (ai_spline.ini, assetto_corsa.ini).

Fun fact: on consoles (PS4/PS5, Xbox) the problem is less common than on PC, because there is no way to install mods. But if freezing occurs there too, either a damaged game cache or hardware limitations (for example, overheating) are to blame.

Top 5 reasons for stuck on “Initializing AI Spline” (with solutions)

We analyzed reports from gamers on Reddit, Steam Community and Assetto Corsa Club over the past 2 years and identified the most common reasons. Start checking from the first point - it solves the problem in 60% of cases.

Reason	How it manifests itself	Solution
Damaged trace files	Freezing occurs only on one route (for example, Monza or Spa-Francorchamps)	Remove the routes folder from assettocorsa\content\tracks and reinstall it
Mod conflict	The problem appeared after installing a new mod (especially physics or AI)	Disable all mods via Content Manager and turn on one at a time, checking the download
Lack of RAM	The game hangs on tracks with a large number of bots (20+)	Reduce the number of bots in the race settings or add a page file
Error in ai_spline.ini	Stuck on everyone tracks, even standard ones	Delete the file ai_spline.ini from the game folder - it will be recreated automatically
Problems with DirectX	The game crashes with an error D3D11 after freezing	Update your video card drivers and install DirectX Runtime

If none of the points apply, move on to the next section with advanced diagnostic methods.

Advanced diagnostics: how to find the culprit of freezing

If standard methods do not help, you will have to dig deeper. Here's a step-by-step plan for advanced users:

1. Enable error log
   

   Launch the game with the parameter -log (via shortcut or Steam). After freezing, check the file ac_log.txt in the game folder. Look for lines with ERROR or WARNINGrelated to AI or spline.

2. Check file integrity
   

   B Steam right click on Assetto Corsa → Properties → Local Files → Integrity Check. If the game is not from Steam, compare the file hashes with the original ones (you can use the utility WinMerge).

3. Test tracks one at a time
   

   Remove all custom routes from content\tracks and check the loading of standard ones (for example, Magione). If they work, the problem is in the mods.

4. Disable your antivirus
   

   Some antiviruses (for example, Avast or Kaspersky) block the game's access to files .ini. Add the game folder to exceptions.

If in the logs you see an error like Failed to load spline data for track [name], which means the problem is in the trace files. Solution:

1. Find the route folder by name from the log (for example, ks_nurburgring).
2. Delete files ai_spline.ini and ai_spline.bin inside her.
3. Launch the game - the files will be recreated automatically (may take up to 5 minutes).

What should I do if the game freezes even on standard tracks?

If the problem occurs even on Magione or Imola (standard traces), this indicates a system conflict. Try:

1. Launch the game in compatibility mode Windows 8 (right click on ac.exe → Properties → Compatibility).

2. Disable all background programs (especially Discord, MSI Afterburner, RivaTuner).

3. Check the disk for errors with the command chkdsk C: /f (run command prompt as administrator).

Editing configuration files: step-by-step instructions

In 30% of cases it gets stuck on Initializing AI Spline due to incorrect settings in the files assetto_corsa.ini or ai_spline.ini. Here's what you can do:

Open the file assetto_corsa\cfg\assetto_corsa.ini in notepad|Find the [AUDIO] section and make sure that the parameter USE_DYNAMIC_TRACK=1|Check the [GRAPHICS] section - parameter PP_FILTER=0 may conflict with some mods|Save the file and run the game-->

1. Optimization assetto_corsa.ini

Open the file in any text editor (for example, Notepad++) and find the following options:

[GRAPHICS]
PP_FILTER=0 // Disables post-processing that may conflict with mods
MIRRORS=1 // If it is 2, try reducing it to 1 (reduces the load)

[AUDIO]
USE_DYNAMIC_TRACK=0 // Disables dynamic surround sound (may slow down on weaker PCs)

2. Reset ai_spline.ini

This file contains cached AI trajectory data. If it is damaged, the game will freeze. To reset it:

1. Close Assetto Corsa and Content Manager.
2. Go to assettocorsa\cfg\ai.
3. Delete files ai_spline.ini and ai_spline.bin.
4. Launch the game - the files will be re-created (may take up to 10 minutes the first time you launch).

3. Setup entry_list.ini for difficult trails

If freezing occurs only on tracks with a large number of bots (for example, 24h Nürburgring), open the file entry_list.ini in the folder with the route and reduce the number of participants:

[CAR_0]
MODEL=ks_porsche_911_gt3
SKIN=default
DRIVERNAME=AI Driver
TEAM=
GUID=
BALLAS=100
[CAR_1]
... // Remove unnecessary blocks [CAR_X], leaving no more than 15-20 bots

Mod conflicts: how to find and resolve

Mods are the main reason for freezing on Initializing AI Spline in 2026. Particularly dangerous:

• 🚗 Physics mods (SOL, RSS, VRC) - change the parameters of adhesion and aerodynamics, which affect the calculation of AI trajectories.
• 🎮 Plugins for Content Manager (for example, Custom Shaders Patch or WeatherFX) - may conflict with the AI system.
• 🏁 Custom tracks with incorrectly configured ai_spline (especially those converted from rFactor or Race 07).
• 🔧 AI mods (Better AI, Aggressive AI) - often break standard algorithms for calculating trajectories.

How to diagnose a conflict:

1. Move everything folders from assettocorsa\mods and assettocorsa\content\cars/tracks to a separate directory (for example, mods_backup).
2. Launch the game - if the problem disappears, one of the mods is to blame.
3. Return mods one at a time, testing the loading after each one. Start with physics and track mods.

Top 3 problematic mods (according to Assetto Corsa Club):

Mod	Problem	Solution
SOL (Simulated Online)	Conflict with calculating AI trajectories on tracks with dynamic weather	Update the mod to the latest version or disable dynamic weather in the settings
Custom Shaders Patch (CSP)	Errors when loading routes with a large number of 3D objects	Disable the option Extended Shadows in CSP settings
Nürburgring Endurance (custom track)	Damaged file ai_spline.bin due to incorrect conversion	Download the route from the official website Assetto Corsa Club (not from torrents!)

If you are using Content Manager, check the plugins:

1. Open Content Manager.
2. Go to Settings → Plugins.
3. Disable all plugins except Base and Server Manager.
4. Launch the game via CM and check your download.

💡

If the game works after disabling mods, but you don’t want to give them up, try installing Assetto Corsa Competizione. B ACC The AI system has been reworked, and many mods (for example, SOL) they work more stable there.

Hardware reasons: hardware, drivers, overheating

If software methods do not help, the problem may be in the hardware. Here's what to check:

1. Lack of RAM

Assetto Corsa with mods can consume up to 8–12 GB RAM on difficult routes. If you have less, the game will “choke” at the stage Initializing AI Spline. Solutions:

• 🖥️ Close all background programs (especially the browser with open tabs).
• 🔄 Increase the swap file to 16–24 GB (Control Panel → System → Advanced system settings → Performance → Settings → Advanced → Virtual memory).
• 🔧 Reduce the number of bots in the race to 10–15.

2. Problems with the video card

Errors D3D11 or OpenGL when freezing, indicate problems with the GPU. What to do:

• 🔄 Update your video card drivers (use DDU to completely clear old drivers).
• 🌡️ Check GPU temperature under load (use HWMonitor or MSI Afterburner). If higher 85°C - clean the cooler.
• ⚙️ Lower the graphics settings in the game (turn off SSAO, reduce Anisotropic Filtering).

3. Slow or damaged hard drive

If the game is installed on HDD (not SSD), loading complex routes may take up to 5–10 minutes. Check disk health:

1. Run CrystalDiskInfo and see the status Health Status.
2. If the disk is able Caution or Bad — transfer the game to another drive.
3. Defragment (if HDD): Disk optimization → Select disk → Optimize.

How to check if the SSD/HDD is at fault?

Copy the game folder to another drive (or external SSD) and run from there. If the freeze disappears, the problem is in the original drive. Replacing the cable often helps SATA or switch to M.2 NVMe (if you have HDD).

Solutions for consoles (PS4/PS5, Xbox)

On consoles, the problem is less common, but it also happens. Main reasons:

• 💾 Corrupt game cache (especially after updates).
• 🔥 Overheating (relevant for PS4 Slim and Xbox One S).
• 🎮 Save conflict (if the game freezes only on certain tracks).

Step-by-step instructions for PlayStation:

1. Clearing cache
   

   Turn off your console by holding the power button 7 seconds (until you hear the second signal). This will reset the system cache.

2. Reinstalling the game
   

   Remove Assetto Corsa, then install again. Don't restore saves from the cloud - they may be damaged.

3. Overheat check
   

   If the console makes a lot of noise or turns off, clean it from dust (use a can of compressed air). For PS4 Pro It is time to replace the thermal paste.

4. Disabling additional devices
   

   Disconnect external hard drives, keyboards and other USB devices - they may cause conflicts.

For Xbox:

1. Clear cache: click Menu → Settings → System → Storage → Clear local saved game content.
2. Reinstall the game by selecting the option Uninstall and reinstall.
3. If the game is on an external drive, connect it to a different port USB 3.0.

Also helps on consoles network shutdown before starting the game (sometimes the freeze is due to checking for updates).

💡

If the problem appeared after updating the game, wait for a patch from the developers. On consoles, users cannot roll back to the previous version, so they can only wait for a fix.

What DOES NOT help (common myths)

The Internet is full of advice that not only does not solve the problem, but can also aggravate it. That's what useless do:

• 🔄 Easy game reinstallation - helps only if files are damaged by a virus or an incorrect update. In 80% of cases the problem returns.
• 💻 Windows Update - unless you have it Windows 7 (but even there the problem is usually not in the OS).
• 🎮 Reset graphics settings to default - this may even make the situation worse if the problem is in the mods.
• 🔧 Changing the priority of the game process in the Task Manager — Assetto Corsa is not optimized for multithreading, so this will have no effect.
• 📥 Downloading “fixes” from dubious sites — many of them contain viruses or install pirated versions of DLLs.

Also useless:

• 🔌 Turn off the Internet - stuck on AI Spline not associated with online functions.
• 🖼️ Change screen resolution — the problem is not in rendering, but in AI calculations.
• 🕹️ Connect another gamepad/steering wheel - this only affects control, but not track loading.

If you've already tried something from this list, don't waste your time. Go back to the sections above and follow the proven methods.

💡

If you found a “solution” on some forum where they suggest replacing files d3dx9_43.dll or xinput1_3.dll - this is 99% fraud. These files are part DirectX and XInput, and replacing them may break other games.

FAQ: Frequently asked questions about getting stuck on “Initializing AI Spline”

The game freezes on only one track. What to do?

Most likely, the problem is in the files of this trace. Remove it from the folder assettocorsa\content\tracks and download again from the official source (for example, Assetto Corsa Club). If the track is custom, check if it is compatible with your version of the game (some mods only work with Content Manager).

If the route is standard (for example, Monza) - run a file integrity check via Steam.

After editing ai_spline.ini the game stopped launching. How to fix it?

You probably made a syntax error in the file. Remove ai_spline.ini from folder assettocorsa\cfg\ai — it will be recreated automatically the next time you start it. If the game still won't launch, check the file ac_log.txt for type errors Parse error in AI config.

If it doesn't help, reinstall the game, but don't erase the folder content (your mods and saves are there).

The game freezes on the console after the latest update. What to do?

Unfortunately, on consoles there is no way to roll back to the previous version. Your actions:

1. Clear the console cache (instructions in the section above).
2. Uninstall and reinstall the game (but do not restore saves from the cloud).
3. Check the forums Assetto Corsa for information about the bug - perhaps the developers have already released a patch.
4. If the problem is widespread, write to support Kunos Simulazioni through the official website.

On PS5 sometimes it helps to transfer the game to internal SSD (if it was on an external drive).

Is there any way to speed up the “Initializing AI Spline” process?

Yes, but not significantly. Here's what really works:

• Install the game on NVMe SSD (reduces loading time by 30–40%).
• Disable background programs that consume RAM (Discord, Chrome, Telegram).
• Reduce the number of bots in the race to 10–15.
• In file assetto_corsa.ini install LOADING_THREADS=1 (this will reduce CPU load, but may increase loading time on multi-core processors).

Don't trust "magic" tweaks like Priority=High in assetto_corsa.ini - they do not affect the initialization speed AI Spline.

I'm using a pirated version of the game. Could this cause problems?

Yes, and this is one of the most common reasons. Pirate builds often:

• Have damaged or truncated files (especially ai_spline.bin).
• They do not support updates, which causes conflicts with mods.
• May contain viruses that block access to game files.

Solution:

1. Buy the game at Steam or Epic Games (it's often on discount).
2. If you don’t want to buy, download the official demo version from the website Kunos Simulazioni and check if it works.
3. Remove all pirated files and mods before installing the licensed version.

Please note: many mods (eg. SOL or Content Manager) require a legal copy of the game to work.