Troubleshooting

Symptom	What to do
Connection refused	Start ComfyUI or correct COMFYUI_BASE_URL.
Missing node or input	Export the workflow again and update the manifest bindings to match its API JSON.
Custom input rejected offline	Match the providerInputs key to a custom binding, keep built-in names reserved, and use a scalar with the same type as the workflow placeholder. Image inputs must target core LoadImage.image or LoadImageMask.image and point to a readable PNG/JPEG.
Prompt validation failed	Open the workflow in ComfyUI and check missing custom nodes, checkpoints, VAEs, LoRAs, and invalid node values.
Wrong image count	Make the bound batch input and numImages describe the same final output count. PixelKiln fails the job rather than recording a partial candidate set.
Frame set stays in review	Deliberate. Accept or reject the ordered set as a unit; PixelKiln never keeps a partial loop.
Frame refinement reports a grid mismatch	Inspect the source renders at integer zoom. Do not resize one frame to hide a step or phase change; fix the workflow controls and regenerate the set.
Out of memory	Lower asset dimensions or batch size, or change the workflow. PixelKiln's 4096px ceiling is a schema limit, not a promise that a particular machine can render that canvas.
The result looks pixelated but muddy	Reject it as source material. Do not upscale it or accept it because grid detection succeeds. Compare a different model, prompt pattern, or smaller native target on at least two scene types.

ComfyUI's official server route reference documents the /prompt, /history/{prompt_id}, /view, and /system_stats endpoints used by this adapter: https://docs.comfy.org/development/comfyui-server/comms_routes.