Troubleshooting

Solutions for common issues and optimization tips to help you get Jan running smoothly.

Troubleshooting

This guide covers common issues you might encounter with Jan and how to resolve them.

Getting Error Logs

Error logs are essential for troubleshooting. You can access them in two ways:

Through Jan Interface

1. Open System Monitor in the footer
2. Choose App Log

Through Terminal

Application Logs:

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

# Linux (alternative path)
tail -n 50 ~/.config/Jan/logs/app.log

Server Logs:

tail -n 50 ~/Library/Application\ Support/Jan/data/logs/cortex.log

Redact any private or sensitive information when sharing logs. We retain logs for only 24 hours.

Common Issues

Broken Build

If Jan is stuck in a broken build after installation:

Mac

1. Uninstall Jan
2. Delete Application Data:

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

3. For versions before 0.4.2, kill background processes:

ps aux | grep nitro
kill -9 <PID>

4. Download the latest version

Windows

1. Uninstall Jan via Control Panel
2. Delete Application Data:

cd C:\Users\%USERNAME%\AppData\Roaming
rmdir /S Jan

3. For versions before 0.4.2, kill background processes:

tasklist | findstr "nitro"
taskkill /F /PID <PID>

4. Download the latest version

Linux

1. Uninstall Jan:

# For Debian/Ubuntu
sudo apt-get remove Jan
# For AppImage: Delete the .AppImage file

2. Delete Application Data:

rm -rf ~/.config/Jan

3. For versions before 0.4.2, kill background processes:

ps aux | grep nitro
kill -9 <PID>

4. Download the latest version

Ensure Jan is completely removed from all user accounts on shared devices before reinstalling.

NVIDIA GPU Not Working

If Jan doesn’t utilize your NVIDIA GPU:

1. Verify Hardware Detection

Windows:

• Right-click desktop → NVIDIA Control Panel
• Or check Device Manager → Display Adapters

Linux:

lspci | grep -i nvidia

2. Install Required Components

NVIDIA Driver (470.63.01 or higher):

1. Install NVIDIA Driver
2. Verify: nvidia-smi

CUDA Toolkit (11.7 or higher):

1. Install CUDA toolkit
2. Verify: nvcc --version

Linux Additional Setup:

sudo apt update
sudo apt install gcc-11 g++-11 cpp-11
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/cuda/lib64

3. Enable GPU Acceleration

1. Open Settings > Hardware
2. Verify GPU Acceleration is enabled
3. Check selected GPU(s) in System Monitor (footer)

4. Check GPU Settings

1. Go to Settings > General > Data Folder
2. Click Open Containing Folder
3. Open settings.json

Verify configuration:

{
  "run_mode": "gpu",
  "nvidia_driver": {
    "exist": true,
    "version": "531.18"
  },
  "cuda": {
    "exist": true,
    "version": "12"
  },
  "gpus": [
    {
      "id": "0",
      "vram": "12282"
    }
  ]
}

“Failed to Fetch” or “Something’s Amiss” Errors

1. Check System Requirements

• Verify your device meets minimum requirements
• RAM: Choose models using less than 80% of available RAM
  • 8GB systems: Models under 6GB
  • 16GB systems: Models under 13GB

2. Adjust Model Parameters

• Check ngl (GPU layers) setting in Engine Settings
• Start with lower values and increase gradually

3. Check Port Conflicts

If logs show “Bind address failed”:

# macOS
netstat -an | grep 39291

# Windows
netstat -ano | find "39291"
tasklist /fi "PID eq 39291"

# Linux
netstat -anpe | grep "39291"

Default Jan ports:

• API Server: 1337
• Documentation: 3001

4. Factory Reset

1. Go to Settings > Advanced Settings
2. Click Reset under Reset To Factory Settings

This deletes all chat history, models, and settings.

5. Clean Installation

• Uninstall Jan and delete data folders
• Download the latest version

Permission Denied Error

If you see permission errors during installation:

sudo chown -R $(whoami) ~/.npm

OpenAI “Unexpected Token” Error

1. API Key Setup

• Get a valid key from OpenAI’s platform
• Ensure sufficient credits and permissions

2. Regional Access

• Use a VPN if in a restricted region
• Verify network access to OpenAI endpoints

Need More Help?

1. Copy your error logs
2. Visit our Discord
3. Post in #🆘|jan-help channel

Check logs before sharing. We retain logs for only 24 hours.