Jan Local Server
Troubleshooting

Troubleshooting

Getting Help: Error Logs

When Jan isn't working properly, error logs help identify the problem. Here's how to get them:

Quick Access to Logs

In Jan Interface:

  1. Look for System Monitor in the footer
  2. Click App Log

App log

Via Terminal:


# macOS/Linux
tail -n 50 ~/Library/Application\ Support/Jan/data/logs/app.log
# Windows
type %APPDATA%\Jan\data\logs\app.log

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Remove any personal information before sharing logs. We only keep logs for 24 hours.

Common Issues & Solutions

Jan Won't Start (Broken Installation)

If Jan gets stuck after installation or won't start properly:

Clean Reinstall Steps:

  1. Uninstall Jan from Applications folder

  2. Delete all Jan data:


rm -rf ~/Library/Application\ Support/Jan

  1. Kill any background processes (for versions before 0.4.2):

ps aux | grep nitro
# Find process IDs and kill them:
kill -9 <PID>

  1. Download fresh copy from jan.ai

Make sure Jan is completely removed from all user accounts before reinstalling.

NVIDIA GPU Not Working

If Jan isn't using your NVIDIA graphics card for acceleration:

Step 1: Check Your Hardware Setup

Verify GPU Detection:

Windows: Right-click desktop → NVIDIA Control Panel, or check Device Manager → Display Adapters

Linux: Run lspci | grep -i nvidia

Install Required Software:

NVIDIA Driver (470.63.01 or newer):

  1. Download from nvidia.com/drivers (opens in a new tab)
  2. Test: Run nvidia-smi in terminal

CUDA Toolkit (11.7 or newer):

  1. Download from CUDA Downloads (opens in a new tab)
  2. Test: Run nvcc --version

Linux Additional Requirements:


# Install required packages
sudo apt update && sudo apt install gcc-11 g++-11 cpp-11
# Set CUDA environment
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/cuda/lib64

Step 2: Enable GPU Acceleration in Jan

  1. Open Settings > Hardware
  2. Turn on GPU Acceleration
  3. Check System Monitor (footer) to verify GPU is detected

Hardware

Step 3: Verify Configuration

  1. Go to Settings > Advanced Settings > Data Folder
  2. Open settings.json file
  3. Check these settings:

{
"run_mode": "gpu", // Should be "gpu"
"nvidia_driver": {
"exist": true, // Should be true
"version": "531.18"
},
"cuda": {
"exist": true, // Should be true
"version": "12"
},
"gpus": [
{
"id": "0",
"vram": "12282" // Your GPU memory in MB
}
]
}

Step 4: Restart Jan

Close and restart Jan to apply changes.

Tested Working Configurations

Desktop Systems:

  • Windows 11 + RTX 4070Ti + CUDA 12.2 + Driver 531.18
  • Ubuntu 22.04 + RTX 4070Ti + CUDA 12.2 + Driver 545

Virtual Machines:

  • Ubuntu on Proxmox + GTX 1660Ti + CUDA 12.1 + Driver 535

Desktop installations perform better than virtual machines. VMs need proper GPU passthrough setup.

"Failed to Fetch" or "Something's Amiss" Errors

When models won't respond or show these errors:

1. Check System Requirements

  • RAM: Use models under 80% of available memory
    • 8GB system: Use models under 6GB
    • 16GB system: Use models under 13GB
  • Hardware: Verify your system meets minimum requirements

2. Adjust Model Settings

  • Open model settings in the chat sidebar
  • Lower the GPU Layers (ngl) setting
  • Start low and increase gradually

3. Check Port Conflicts If logs show "Bind address failed":


# Check if ports are in use
# macOS/Linux
netstat -an | grep 1337
# Windows
netstat -ano | find "1337"

Default Jan ports:

  • API Server: 1337
  • Documentation: 3001

4. Try Factory Reset

  1. Settings > Advanced Settings
  2. Click Reset under "Reset To Factory Settings"
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This deletes all chat history, models, and settings.

5. Clean Reinstall If problems persist, do a complete clean installation (see "Jan Won't Start" section above).

Permission Denied Errors

If you see permission errors during installation:


# Fix npm permissions (macOS/Linux)
sudo chown -R $(whoami) ~/.npm
# Windows - run as administrator

OpenAI API Issues ("Unexpected Token")

For OpenAI connection problems:

1. Verify API Key

2. Check Regional Access

  • Some regions have API restrictions
  • Try using a VPN from a supported region
  • Test network connectivity to OpenAI endpoints

Performance Issues

Models Running Slowly:

  • Enable GPU acceleration (see NVIDIA section)
  • Use appropriate model size for your hardware
  • Close other memory-intensive applications
  • Check Task Manager/Activity Monitor for resource usage

High Memory Usage:

  • Switch to smaller model variants
  • Reduce context length in model settings
  • Enable model offloading in engine settings

Frequent Crashes:

  • Update graphics drivers
  • Check system temperature
  • Reduce GPU layers if using GPU acceleration
  • Verify adequate power supply (desktop systems)

Need More Help?

If these solutions don't work:

1. Gather Information:

  • Copy your error logs (see top of this page)
  • Note your system specifications
  • Describe what you were trying to do when the problem occurred

2. Get Community Support:

3. Check Resources:

When sharing logs, remove personal information first. We only keep logs for 24 hours, so report issues promptly.

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