Introduction

After updating your system or software, you might encounter issues where images become completely black during certain workflows in ComfyUI. This guide will help you resolve this problem specifically related to the use of the Karras scheduler.

Step 1: Understand the Cause

The issue is likely due to a compatibility or configuration problem with the Karras scheduler after recent updates. The Karras scheduler is used for generating high-quality images and might not be properly configured post-update, leading to black images in ComfyUI.

Step 2: Identify Affected Components

To narrow down the issue, you need to confirm that it’s related specifically to the Karras scheduler. Check if other schedulers like Euler or DDIM work without issues.

1. Switch Schedulers: Test your workflows with different schedulers (Euler, DDIM) and observe whether black images still occur.
2. Check Logs: Look into ComfyUI logs for any error messages related to the Karras scheduler or rendering process.

Step 3: Update Dependencies

Ensure all dependencies are up-to-date:

1. Open a terminal.
2. Navigate to your ComfyUI directory.
3. Run the following commands to update dependencies:

   pip install --upgrade pillow
   pip install --upgrade torch torchvision

These updates can help resolve compatibility issues that may have caused by recent changes in software libraries.

Step 4: Adjust Configuration Settings

Adjust settings related to image generation and rendering:

1. Restart ComfyUI: Sometimes simply restarting the application after updating dependencies resolves unexpected issues.
2. Change Scheduler: Temporarily switch to a different scheduler (e.g., Euler) if Karras continues causing problems.

Step 5: Fix or Update the Karras Scheduler

If switching schedulers is not an option, you may need to adjust how ComfyUI handles the Karras scheduler:

1. Check for Specific Fixes: Look for any patches or fixes released by developers that address issues with recent versions of ComfyUI and Karras.
2. Manual Adjustments: If no specific fix exists, try manually tweaking configurations related to the Karras scheduler in your scripts or settings file (if applicable).

Step 6: Report Issue

If you have tried all these steps and the problem persists, consider reporting a detailed issue on ComfyUI’s GitHub repository. Include the following details:

• Steps that reproduce the error.
• Information about your system (Mac mini M2 Pro with Sonoma 14.5).
• Any relevant log files or error messages.

By providing comprehensive information, you can help developers identify and fix this issue for future updates.

Conclusion

Following these steps should resolve the black image issue when using ComfyUI on a Mac mini M2 Pro with Sonoma 14.5 after recent updates. If the problem remains unresolved, please reach out to the ComfyUI community or support channels for further assistance.