How to Troubleshoot and Solve ComfyUI Issues

Troubleshoot and fix problems caused by custom nodes and extensions

Quick Issue Diagnosis

If you’re experiencing any of these issues, there is a high likelihood that it is caused by custom nodes:

• ComfyUI crashes or won’t start
• “Failed to import” errors in console/logs
• UI completely breaks or shows blank screen
• “Prompt execution failed” errors not related to memory issues
• Missing nodes that should be available/installed

Is It a Custom Node Problem?

Most ComfyUI issues are caused by custom nodes (extensions). Let’s check if this is the case.

Step 1: Test with all custom nodes disabled

Run ComfyUI with all custom nodes disabled:

Desktop Users

Start ComfyUI Desktop with custom nodes disabled from the settings menu

or run the server manually:

cd path/to/your/comfyui
python main.py --disable-all-custom-nodes

Results:

• ✅ Issue disappears: A custom node is causing the problem → Continue to Step 2
• ❌ Issue persists: Not a custom node issue → Report the issue

Step 2: Find the Problematic Custom Node

We’ll use binary search to quickly find which custom node is causing issues. This is much faster than testing nodes one by one.

Option A: Using Comfy CLI (Recommended)

If you have Comfy CLI installed, you can use the automated bisect tool to find the problematic node:

# Start a bisect session
comfy-cli node bisect start

# Follow the prompts:
# - Test ComfyUI with the current set of enabled nodes
# - Mark as 'good' if the issue is gone: comfy-cli node bisect good
# - Mark as 'bad' if the issue persists: comfy-cli node bisect bad
# - Repeat until the problematic node is identified

# Reset when done
comfy-cli node bisect reset

The bisect tool will automatically enable/disable nodes and guide you through the process.

Option B: Manual Binary Search

If you prefer to do the process manually or don’t have Comfy CLI installed, follow the steps below:

How Binary Search Works

Instead of testing each node individually (which could take hours), we split the nodes in half repeatedly:

8 nodes → Test 4 nodes → Test 2 nodes → Test 1 node ✓

Example with 8 nodes:
1. Test nodes 1-4: Issue persists ✓ → Problem in remaining nodes 5-8
2. Test nodes 5-6: Issue gone ✓ → Problem in nodes 7-8  
3. Test node 7: Issue persists ✓ → Node 7 is the problem!

This takes only 3 tests instead of testing all 8 nodes individually.

Binary Search Process

Before starting, create a backup of your custom_nodes folder in case something goes wrong.

Create Temporary Folders

Windows

# Create backup and temporary folder
mkdir "%USERPROFILE%\custom_nodes_backup"
mkdir "%USERPROFILE%\custom_nodes_temp"

# Backup everything first
xcopy "custom_nodes\*" "%USERPROFILE%\custom_nodes_backup\" /E /H /Y

Find the Problematic Node

1. List your custom nodes:

   Windows

   dir custom_nodes
   

2. Split nodes in half:

   Let’s say you have 8 custom nodes. Move the first half to temporary storage:

   Windows

   # Move first half (nodes 1-4) to temp
   move "custom_nodes\node1" "%USERPROFILE%\custom_nodes_temp\"
   move "custom_nodes\node2" "%USERPROFILE%\custom_nodes_temp\"
   move "custom_nodes\node3" "%USERPROFILE%\custom_nodes_temp\"
   move "custom_nodes\node4" "%USERPROFILE%\custom_nodes_temp\"
   

3. Test ComfyUI:

   python main.py
   

4. Interpret results:

   • Issue persists: Problem is in the remaining nodes (5-8)
   • Issue gone: Problem was in the moved nodes (1-4)

5. Narrow it down:

   • If issue persists: Move half of remaining nodes (e.g., nodes 7-8) to temp
   • If issue gone: Move half of temp nodes (e.g., nodes 3-4) back to custom_nodes

6. Repeat until you find the single problematic node

Visual Example

Let’s walk through a complete example with 8 custom nodes:

📁 custom_nodes/
├── 🔧 ComfyUI-Manager
├── 🎨 ComfyUI-Custom-Scripts  
├── 🖼️ ComfyUI-Impact-Pack
├── 🔄 ComfyUI-Workflow-Component
├── 📊 ComfyUI-AnimateDiff-Evolved
├── 🎭 ComfyUI-FaceRestore
├── ⚡ ComfyUI-Advanced-ControlNet
└── 🛠️ ComfyUI-Inspire-Pack

Round 1: Move first 4 to temp

• Test → Issue persists ✓
• Problem is in: ComfyUI-AnimateDiff-Evolved, ComfyUI-FaceRestore, ComfyUI-Advanced-ControlNet, ComfyUI-Inspire-Pack

Round 2: Move 2 of the remaining 4 to temp

• Test → Issue gone ✓
• Problem is in: ComfyUI-Advanced-ControlNet, ComfyUI-Inspire-Pack

Round 3: Move 1 of the remaining 2 to temp

• Test → Issue persists ✓
• Found it! ComfyUI-Inspire-Pack is the problematic node

Step 3: Fix the Issue

Once you’ve identified the problematic custom node:

Option 1: Update the Node

1. Check if there’s an update available in ComfyUI Manager
2. Update the node and test again

Option 2: Replace the Node

1. Look for alternative custom nodes with similar functionality
2. Check the ComfyUI Registry for alternatives

Option 3: Report the Issue

Contact the custom node developer:

1. Find the node’s GitHub repository
2. Create an issue with:
   • Your ComfyUI version
   • Error messages/logs
   • Steps to reproduce
   • Your operating system

Option 4: Remove or Disable the Node

If no fix is available and you don’t need the functionality:

1. Remove the problematic node from custom_nodes/ or disable it in the ComfyUI Manager interface
2. Restart ComfyUI

Reporting Issues

If the issue isn’t caused by custom nodes, refer to the general troubleshooting overview for other common problems.

For Custom Node-Specific Issues

Contact the custom node developer:

• Find the node’s GitHub repository
• Create an issue with your ComfyUI version, error messages, reproduction steps, and OS
• Check the node’s documentation and Issues page for known issues

For ComfyUI Core Issues

• GitHub: ComfyUI Issues
• Forum: Official ComfyUI Forum

For Desktop App Issues

• GitHub: ComfyUI Desktop Issues

For Frontend Issues

• GitHub: ComfyUI Frontend Issues

For general installation, model, or performance issues, see our troubleshooting overview and model issues pages.