Comfy-Org/ComfyUI_Nvidia_VFX_Nodes
1
0
Fork 0
mirror of https://github.com/Comfy-Org/ComfyUI_Nvidia_VFX_Nodes.git synced 2026-11-04 23:37:30 +00:00
Code Issues 31 Projects Packages Wiki Activity

[GH-ISSUE #21] [ISSUE] Save Image node says "Required Input is missing: Images" when connected to RTX node but only in Z-Image workflows. #18

New issue
Closed
opened 2026-10-26 22:28:01 +00:00 by bsakaguchi · 3 comments
bsakaguchi commented 2026-10-26 22:28:01 +00:00
Owner
Copy link

Originally created by @ghost on GitHub (Mar 19, 2026).
Original GitHub issue: https://github.com/Comfy-Org/ComfyUI_Nvidia_VFX_Nodes/issues/21

I have an Upscale workflow that uses the RTX node that works just fine. Load Image > RTX Node > Save Image

I have 2 Z-Image workflows that used to upscale with a model but I wanted to use the RTX node instead because it's better. But when I have the Save Image node connected to the RTX Node for the final output, the Save Image node turns red with the error shown in the title. Same thing happens with the Preview Image node.

If I replace Save Image with the Save Image (Simple) node, it works fine.

NOTE: I thought I had siscovered the cause of the problem but I haven't. I thought it might have been an issue with the VAE passing incompatible data to the RTX node so I changed it to VAE Decode Tiled and that worked but only in one of the Z-Image workflows. The other still fails even with that change.

Qwen workflows seem to work fine, I have a Flux2-Klein 9B workflow that also seems to work fine. It definitely appears to be Z-Image related but the inconsistency is throwing a curve-ball. I'm fairly new to ComfyUI so this could be well out of my league but I will try and provide further diagnostic information as I get it. The log isn't going to be much use because the only related error is this:

Failed to validate prompt for output 9:
* (prompt):
  - Required input is missing: images
* SaveImage 9:
  - Required input is missing: images
Output will be ignored

That's it, that's all it says. The nodes are obviously loading and working because they do work in some workflows.

I have attached the workflow that fails. I have tried it in 3 different Comfy installs and it fails in each one. There's nothing complex or unusual in it but it just refuses to work.

Z-Image with RTX (FAIL).json

Originally created by @ghost on GitHub (Mar 19, 2026). Original GitHub issue: https://github.com/Comfy-Org/ComfyUI_Nvidia_VFX_Nodes/issues/21 I have an Upscale workflow that uses the RTX node that works just fine. Load Image > RTX Node > Save Image I have 2 Z-Image workflows that used to upscale with a model but I wanted to use the RTX node instead because it's better. But when I have the Save Image node connected to the RTX Node for the final output, the Save Image node turns red with the error shown in the title. Same thing happens with the Preview Image node. If I replace Save Image with the Save Image (Simple) node, it works fine. NOTE: I thought I had siscovered the cause of the problem but I haven't. I thought it might have been an issue with the VAE passing incompatible data to the RTX node so I changed it to VAE Decode Tiled and that worked but only in one of the Z-Image workflows. The other still fails even with that change. Qwen workflows seem to work fine, I have a Flux2-Klein 9B workflow that also seems to work fine. It definitely appears to be Z-Image related but the inconsistency is throwing a curve-ball. I'm fairly new to ComfyUI so this could be well out of my league but I will try and provide further diagnostic information as I get it. The log isn't going to be much use because the only related error is this: ``` Failed to validate prompt for output 9: * (prompt): - Required input is missing: images * SaveImage 9: - Required input is missing: images Output will be ignored ``` That's it, that's all it says. The nodes are obviously loading and working because they do work in some workflows. I have attached the workflow that fails. I have tried it in 3 different Comfy installs and it fails in each one. There's nothing complex or unusual in it but it just refuses to work. [Z-Image with RTX (FAIL).json](https://github.com/user-attachments/files/26102770/Z-Image.with.RTX.FAIL.json)
bsakaguchi commented 2026-10-26 22:28:02 +00:00
Author
Owner
Copy link

@nnqq2603 commented on GitHub (Mar 26, 2026):

I tried your json file and notice the flux resolution node not installed in my local system so I removed it and change the Z model loader to gguf (since my graphic card is small can't handle that Z model you used), and the workflow just run, nothing wrong technically, no error. Are you sure the resolution custom node didn't just malfunction cause the whole pipeline collapse?

Image You can try create it from scatch.
<!-- gh-comment-id:4132440416 --> @nnqq2603 commented on GitHub (Mar 26, 2026): I tried your json file and notice the flux resolution node not installed in my local system so I removed it and change the Z model loader to gguf (since my graphic card is small can't handle that Z model you used), and the workflow just run, nothing wrong technically, no error. Are you sure the resolution custom node didn't just malfunction cause the whole pipeline collapse? <img width="4096" height="2048" alt="Image" src="https://github.com/user-attachments/assets/8ae53aa5-6042-46cd-b386-0bb22c201a05" /> You can try create it from scatch.
bsakaguchi commented 2026-10-26 22:28:02 +00:00
Author
Owner
Copy link

@ghost commented on GitHub (Mar 26, 2026):

Gah! AI can be so frustrating at times, I just tried rebuilding this workflow again from scratch, which is basically what I did to create this sample workflow that failed... except now it works.

It's like the old days when colour TV was first introduced and you'd call the TV engineer out for a fault and the fault never happened while they were there.

Maybe I am just too old for all this now, sorry about that. ☹

I'll close this to avoid wasting anyone else's time.

<!-- gh-comment-id:4135470216 --> @ghost commented on GitHub (Mar 26, 2026): Gah! AI can be so frustrating at times, I just tried rebuilding this workflow again from scratch, which is basically what I did to create this sample workflow that failed... except now it works. It's like the old days when colour TV was first introduced and you'd call the TV engineer out for a fault and the fault never happened while they were there. Maybe I am just too old for all this now, sorry about that. ☹ I'll close this to avoid wasting anyone else's time.
bsakaguchi commented 2026-10-26 22:28:03 +00:00
Author
Owner
Copy link

@GRAYgoose124 commented on GitHub (Jun 26, 2026):

I had this problem with Image Edit (Flux 2 Klein 4B Distilled) node.

I unpaused it, but upon viewing the subgraph, noticed the subnodes were still paused, Unpausing those subnodes that eventually output to image fixed my workflow.

<!-- gh-comment-id:4813077964 --> @GRAYgoose124 commented on GitHub (Jun 26, 2026): I had this problem with Image Edit (Flux 2 Klein 4B Distilled) node. I unpaused it, but upon viewing the subgraph, noticed the subnodes were still paused, Unpausing those subnodes that eventually output to image fixed my workflow.
Sign in to join this conversation.
No Branch/Tag specified
Branches Tags
main
alexis/rename-true-hdr-to-video-hdr
Revert-node-name
alexis/add-long-video-true-hdr-workflow
alexis/add-node-thumbnails-readme
alexis/add-video-upscale-thumbnail
alexis/update-workflow-thumbnails
alexis/update-workflows
Update-README
alexis/update-tru-hdr-workflow
alexis/update-vfx-nodes
alexis/update-pyproject
add-publish-workflow-and-pyproject
No results found.
Labels
Clear labels   
pull-request
Mirrored from GitHub Pull Request

No labels
pull-request
Milestone
Clear milestone
No items
No milestone
Projects
Clear projects
No items
No project
Assignees
Clear assignees
No assignees
1 participant
Notifications
Due date
The due date is invalid or out of range. Please use the format "yyyy-mm-dd".

No due date set.

Dependencies

No dependencies set.

Reference
Comfy-Org/ComfyUI_Nvidia_VFX_Nodes#18
No description provided.