Comfy-Org / Comfy-Org/ComfyUI

Frequently black/grey images and NaN latent errors across multiple models. Persists after factory reset. Affects Windows and Linux systems.

Open
#13,116 10 comments 0 reactions 1 assignee Claimed by @rattus128 View on GitHub
User Support
Dominant language
Python
Stars
133k
Forks
15.7k
Avg merge
1d 7h
Merged PRs (30d)
158

Description

### Custom Node Testing

- [x] I have tried disabling custom nodes and the issue persists (see [how to disable custom nodes](https://docs.comfy.org/troubleshooting/custom-node-issues#step-1%3A-test-with-all-custom-nodes-disabled) if you need help)

### Your question

Field | Value
-- | --
ComfyUI Version | 0.17.2
ComfyUI Frontend | v1.41.20
ComfyUI Manager | V3.39.2
OS | Windows 32-bit (win32)
Python Version | 3.13.11 (Dec 5 2025) [MSC v.1944 64-bit AMD64]
PyTorch Version | 2.10.0+cu130
GPU | NVIDIA GeForce RTX 5080 (15.92 GB VRAM)
RAM | 61.6 GB

Generations across multiple model types (SDXL, Wan 2.1/2.2, Flux2 Klein 9b fp8) frequently produce black/grey images, NaN latent errors, or heavily distorted/noisy outputs. This is a **regression** - these issues were not present previously with the same hardware. The problem persists across clean installs, driver changes, and even after a full PC factory reset. It also persists across WSL2 and even dual-boot ubuntu installs.

## Issues by Model

### SDXL

- Generating at **1024×1024 or higher** frequently results in completely black or grey images (not 100% of the time)
- In a batch of 4 images, typically only **1 or 2 renders correctly** - the rest are black/grey
- Reducing resolution reliably decreases the error rate
- Reproduced in both **ComfyUI** and **sd-webui-forge-neo**

ComfyUI will *occasionally*, not consistently, report an error like this: ```ComfyUI_windows_portable\ComfyUI\nodes.py:1664: RuntimeWarning: invalid value encountered in cast
img = Image.fromarray(np.clip(i, 0, 255).astype(np.uint8))```

### Flux.2 Klein 9b fp8

- Generally works, but **~10% of generations** exhibit obvious distortion or random latent noise
- Issue is exacerbated by LORAs
- Occasionally enters a state where it **only generates black/grey images** - restarting ComfyUI usually resolves this
- Previously, Klein would *only* work with zero LORAs active; this was resolved after a full PC factory reset, but the other issues persist.

### Wan 2.2
- Once I reach a certain threshold with resolution and/or length, my generations either become super glitchy/noisy or just completely black.
- The threshold before it becomes too distorted is around 480x480 at length 49. Length at 53 becomes noisy, and 57 or higher turns black.
- These numbers are variable depending on the res and length, lower res = longer length and vice versa.

### Logs

```powershell
At launch logs:

comfy_kitchen backend eager: {'available': True, 'disabled': False, 'unavailable_reason': None, 'capabilities': ['apply_rope', 'apply_rope1', 'dequantize_mxfp8', 'dequantize_nvfp4', 'dequantize_per_tensor_fp8', 'quantize_mxfp8', 'quantize_nvfp4', 'quantize_per_tensor_fp8', 'scaled_mm_mxfp8', 'scaled_mm_nvfp4']}
Found comfy_kitchen backend cuda: {'available': True, 'disabled': False, 'unavailable_reason': None, 'capabilities': ['apply_rope', 'apply_rope1', 'dequantize_nvfp4', 'dequantize_per_tensor_fp8', 'quantize_mxfp8', 'quantize_nvfp4', 'quantize_per_tensor_fp8', 'scaled_mm_nvfp4']}
Found comfy_kitchen backend triton: {'available': False, 'disabled': True, 'unavailable_reason': "ImportError: No module named 'triton'", 'capabilities': []}
Checkpoint files will always be loaded safely.
Total VRAM 16303 MB, total RAM 63081 MB
pytorch version: 2.10.0+cu130
Set vram state to: NORMAL_VRAM
Device: cuda:0 NVIDIA GeForce RTX 5080 : cudaMallocAsync
Using async weight offloading with 2 streams
Enabled pinned memory 28386.0
working around nvidia conv3d memory bug.
Using pytorch attention
aimdo: src-win/cuda-detour.c:77:INFO:aimdo_setup_hooks: found driver at 00007FFDEFE30000, installing 4 hooks
aimdo: src-win/cuda-detour.c:61:DEBUG:install_hook_entrys: hooks successfully installed
aimdo: src/control.c:69:INFO:comfy-aimdo inited for GPU: NVIDIA GeForce RTX 5080 (VRAM: 16302 MB)
DynamicVRAM support detected and enabled
Python version: 3.13.11 (tags/v3.13.11:6278944, Dec 5 2025, 16:26:58) [MSC v.1944 64 bit (AMD64)]
ComfyUI version: 0.17.2
comfy-aimdo version: 0.2.10
comfy-kitchen version: 0.2.8
ComfyUI frontend version: 1.41.20

Log for first Wan2.2 gen (480x480 length 57, black video):

Using pytorch attention in VAE
Using pytorch attention in VAE
VAE load device: cuda:0, offload device: cpu, dtype: torch.bfloat16
Found quantization metadata version 1
Using MixedPrecisionOps for text encoder
CLIP/text encoder model load device: cuda:0, offload device: cpu, current: cpu, dtype: torch.float16
Requested to load WanTEModel
Model WanTEModel prepared for dynamic VRAM loading. 6419MB Staged. 0 patches attached. Force pre-loaded 49 weights: 392 KB.
Model WanTEModel prepared for dynamic VRAM loading. 6419MB Staged. 0 patches attached. Force pre-loaded 49 weights: 392 KB.
Requested to load WanVAE
Model WanVAE prepared for dynamic VRAM loading. 242MB Staged. 0 patches attached. Force pre-loaded 52 weights: 28 KB.
Found quantization metadata version 1
Detected mixed precision quantization
Using mixed precision operations
model weight dtype torch.float16, manual cast: torch.float16
model_type FLOW
WARNING: No VAE weights detected, VAE not initalized.
no CLIP/text encoder weights in checkpoint, the text encoder model will not be loaded.
Requested to load WAN21
Model WAN21 prepared for dynamic VRAM loading. 13853MB Staged. 0 patches attached.
100%|████████████████████████████████████████████████████████████████████████████████████| 2/2 [00:00<00:00, 3.31it/s]
Found quantization metadata version 1
Detected mixed precision quantization
Using mixed precision operations
model weight dtype torch.float16, manual cast: torch.float16
model_type FLOW
WARNING: No VAE weights detected, VAE not initalized.
no CLIP/text encoder weights in checkpoint, the text encoder model will not be loaded.
Requested to load WAN21
0 models unloaded.
Model WAN21 prepared for dynamic VRAM loading. 13853MB Staged. 0 patches attached.
100%|████████████████████████████████████████████████████████████████████████████████████| 2/2 [00:02<00:00, 1.07s/it]
0 models unloaded.
Model WanVAE prepared for dynamic VRAM loading. 242MB Staged. 0 patches attached. Force pre-loaded 52 weights: 28 KB.
Prompt executed in 63.09 seconds

Log for second wan2.2 gen (same settings apart from noise_seed, seemingly perfect non-glitchy video)

got prompt
Model WanVAE prepared for dynamic VRAM loading. 242MB Staged. 0 patches attached. Force pre-loaded 52 weights: 28 KB.
Model WAN21 prepared for dynamic VRAM loading. 13853MB Staged. 0 patches attached.
100%|████████████████████████████████████████████████████████████████████████████████████| 2/2 [00:00<00:00, 3.36it/s]
0 models unloaded.
Model WAN21 prepared for dynamic VRAM loading. 13853MB Staged. 0 patches attached.
100%|████████████████████████████████████████████████████████████████████████████████████| 2/2 [00:00<00:00, 3.69it/s]
0 models unloaded.
Model WanVAE prepared for dynamic VRAM loading. 242MB Staged. 0 patches attached. Force pre-loaded 52 weights: 28 KB.
Prompt executed in 24.73 seconds
```

### Other

## What Has Been Tried

### No Effect

- Installing older versions of ComfyUI
- Re-downloading all models, VAEs, and text encoders
- Clean reinstall of NVIDIA GPU drivers using DDU
- Installing older NVIDIA driver versions
- Switching from Game Ready to Studio drivers
- Updating AMD chipset drivers
- Closing all background applications
- Disabling GPU scheduling
- Disabling hardware acceleration in browser
- Disabling windowed optimizations
- Removing all external CUDA/PyTorch/Python installs outside the portable/venv directory
- Running ComfyUI with various precision/memory flags: `--force-fp32`, `--force-fp16`, `--fp16-vae`, `--bf16-vae`, `--split-cross-attention`, `--quad-cross-attention`, `--pytorch-cross-attention`, `--disable-xformers`, `--gpu-only`, `--lowvram`
- Running ComfyUI inside WSL2
- Running ComfyUI on a dual-boot Ubuntu install
- Full PC factory reset *(partially helped — see below)*

### Partially or Temporarily Effective

- Running VAE on CPU | Reliably fixes SDXL black image issue, but is far too slow for Wan or Klein (and slow for SDXL in practice)
- `--disable-smart-memory` | Appeared to improve Wan 2.2 temporarily; no longer has any noticeable effect. Consistently improves SDXL black image generation
- Enabling live preview (TAESD or latent) | The first time I tried this it completely resolved the issue until the next PC restart - no longer effective even after toggling
- Full PC factory reset | Fixed the "Klein refuses to run with any LORA" issue specifically; did not fix the other issues

## Key Concerns

1. **A full PC factory reset did not resolve the core issues** - suggesting this is not a software environment problem
2. **The issue persists inside WSL2 and Ubuntu installs**, likely ruling out most Windows-specific or driver-level causes
3. **Some fixes worked completely, then stopped working** after a restart (e.g. live preview enabling) - suggesting something non-deterministic or state-dependent is occurring
4. **No issues occur in other VRAM/CUDA-intensive software** (e.g. Blender rendering), making hardware defects unlikely
5. The issue is a **regression** - identical hardware and workflows that previously ran without problems are now consistently failing

Contributor guide

Open the contributing guide

Assessment

This issue has not been assessed yet.

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.