ComfyUI missing custom nodes
Identify unavailable node classes without installing an unrelated package.
Recognize the message
Missing node types; node class not found
A workflow references a class your running ComfyUI has not registered. It may be absent, disabled, renamed or failing to import. A package directory on disk is not proof that its node loaded.
Work through the evidence
- Export the original workflow and list the exact missing class names. Keep the startup traceback and the version of ComfyUI and the extension.
- Check the original workflow author’s documented dependencies and official extension repository. Match class names rather than guessing from the displayed node title.
- Inspect startup errors first. If the extension is installed but its import fails, follow its documented environment requirements; avoid installing packages into a different Python environment.
Verify the result
Restart ComfyUI after a justified change, confirm that the missing class appears in the node menu, reopen the copied graph, and queue a small job.
What this does not prove
A missing model file is a loader problem, not a missing class. OnBeg can report referenced names but cannot safely identify every extension package or install it for you.
Inspect before changing your workflow
The log inspector works in your browser. The workflow checker reads exported graph structure. Neither sends files automatically or executes nodes. Preserve the original, inspect a copy and record the actual test result in Casebook.
Inspect your log ↗ · Check the graph ↗ · Record a recovery case ↗Before asking for help
Include the first full exception, the failing stage, software versions, model family and the smallest reproducible graph. Redact API keys, user paths and private prompts. A summary such as “KSampler broken” removes the context that distinguishes one failure from another.
Prepare a redacted copy ↗Related investigations
ComfyUI CUDA out of memory · ComfyUI model not found · ComfyUI custom node import failed · ComfyUI tensor shape mismatch
Source and scope
These are OnBeg’s diagnostic checklists, informed by official ComfyUI troubleshooting. They are not universal fixes and do not replace model- or extension-specific instructions.