ComfyUI Plugin Import Failed: Fix Custom Node Errors

If ComfyUI starts but custom nodes do not load, the plugin was probably downloaded, but the Python process that starts ComfyUI could not import it safely.

If you searched for comfyui plugin import failed, the short answer is:

• identify the exact plugin and traceback first
• fix the earliest import failure, not the red node you noticed later
• install packages only in the Python environment that actually launches ComfyUI
• treat this as a dependency or packaging problem first, not as proof that all of ComfyUI is broken

That usually means one of four things:

• A required Python package is missing
• A plugin installed an incompatible dependency
• Torch or another core package was downgraded
• The plugin repo is stale, moved, or only partially installed

Highest-signal plugin import failures

These are the plugin-import patterns that show up most often in real support and launcher troubleshooting:

It is useful to separate three symptoms that often get mixed together:

Fix the earliest failing layer first. Installing packages for a runtime error will not help if the plugin never registered its nodes.

The good news is that plugin import failed does not always mean you must reinstall ComfyUI. In most cases, you can classify the failure, repair the environment, and keep your existing workflows and models.

What "plugin import failed" usually looks like

You will usually see one or more of these symptoms:

• IMPORT FAILED in the startup log
• A custom node folder exists, but none of its nodes appear in ComfyUI
• The workflow opens with red nodes after restart
• A node worked before, then stopped loading after another plugin install
• ComfyUI Desktop or a portable build becomes unstable after adding custom nodes

Typical log lines look like this:

IMPORT FAILED: ComfyUI-ExampleNode
ModuleNotFoundError: No module named 'somepackage'

or:

IMPORT FAILED: ComfyUI-AnotherNode
ImportError: DLL load failed while importing cv2

or:

IMPORT FAILED: ComfyUI-SomePlugin
AttributeError: module 'torch' has no attribute '...'

Step 1: Confirm which plugin actually failed

Do not start by installing random packages.

First, answer two questions:

1. Which plugin failed to import?
2. What exact error type stopped the import?

Check these places in order:

Startup log

Look for IMPORT FAILED and copy the full traceback. That tells you which plugin broke and what Python object could not be imported.

ComfyUI import failure API

If ComfyUI still launches far enough to open the UI, visit:

http://127.0.0.1:8188/v2/customnode/import_fail_info_bulk

This returns a JSON list of custom node import failures.

Workflow symptoms

If the workflow shows red nodes, note whether:

• only one plugin family is missing
• multiple unrelated plugins are missing
• the same plugin worked before another install changed the environment

That pattern helps you decide whether the problem is isolated or global.

Step 2: Classify the failure before you fix it

Most plugin import failures fall into one of these buckets.

Missing package

Example:

ModuleNotFoundError: No module named 'onnxruntime'

This is usually the simplest case. The plugin expects a package that is not installed.

Broken binary package

Example:

ImportError: DLL load failed while importing cv2

The package may be installed, but the binary wheel does not match your Python, CUDA, or Windows runtime.

Core dependency drift

Example:

AttributeError: module 'torch' has no attribute '...'

This often means another plugin install changed a core package like torch, numpy, pillow, or opencv-python.

Repo or source problem

Example:

• The repo moved
• The plugin was only partially cloned
• Git LFS left placeholder files behind
• The plugin is too old for your current ComfyUI version

Before you run any install command

Check these three things first:

1. Did the plugin ever work on this machine?
2. Is the plugin folder present but broken, or completely missing?
3. Did another plugin install happen right before this import started failing?

That short timeline often tells you whether you should treat the problem as a missing package, dependency drift, or source compatibility break.

Common package-specific routes

If the traceback names one of these packages, use the narrow guide before running broad plugin requirements:

Step 3: Repair the environment manually

Once you know the failure class, use the narrowest fix possible.

If a package is missing

Install the missing package, but do it in the same Python environment that starts ComfyUI:

Then restart ComfyUI and test again.

If the package is known to be sensitive or heavy, prefer a pinned install or a wheel recommended by the plugin author.

If you suspect dependency drift

Run:

pip check

Look for conflicts around:

• torch
• torchvision
• torchaudio
• numpy
• pillow
• opencv-python
• transformers
• diffusers

If one plugin install changed one of those, repair the core package first, then test the failing plugin again.

For a broader walkthrough, see ComfyUI Dependency Conflicts.

If the plugin itself is outdated or partially broken

Go to the plugin folder under custom_nodes/ and verify:

• the repo is the right one
• the source files are real code, not Git LFS pointers
• the plugin still supports your ComfyUI version
• the plugin README does not require extra manual packages

If necessary:

cd custom_nodes/<plugin-name>
git pull

Then reinstall only that plugin's requirements — but with caution:

For the official Windows portable package, prefer running from the portable package root with .\python_embeded\python.exe -s -m pip install -r .\ComfyUI\custom_nodes\<plugin-name>\requirements.txt.

Step 4: Know when the command-line loop is making things worse

Manual repair is valid, but it gets expensive once you are doing this repeatedly:

• install one package
• restart ComfyUI
• hit a new import failure
• install another package
• break Torch
• repair Torch
• lose track of what changed

That is exactly where many users end up reinstalling even when the environment was technically recoverable.

When this is really a dependency-conflict problem

If one plugin import failure turns into several unrelated plugin failures after a package install, you are usually no longer dealing with a single plugin bug.

That is the point to switch to:

• ComfyUI Dependency Conflicts
• Repair ComfyUI Portable Dependencies One Missing Module At A Time

How Wonderful Launcher helps

Wonderful Launcher can detect and fix this issue automatically. It manages your ComfyUI environment safely — isolating dependencies, recovering broken installations, and preventing conflicts.

Download Wonderful Launcher — it's free.

A safer recovery path with Wonderful Launcher

Wonderful Launcher is built for the stage where ComfyUI is already messy.

Instead of treating the problem as "install a plugin and hope", the launcher is meant to help you:

• take over an existing Desktop or portable install
• recover from plugin import failures with less command-line hopping
• reduce reinstall risk when workflows, models, and custom nodes already exist
• move from self-recovery to expert help without changing tools

When to escalate to expert help

Use expert help if:

• multiple unrelated plugins fail at once
• startup failures appear after plugin repair attempts
• Torch, CUDA, or OpenCV were already changed by previous fixes
• you cannot tell whether the problem is the repo, the environment, or the workflow

That is where live recovery is usually faster than another evening of trial and error.

Related guides

• ComfyUI Startup Failed? How to Diagnose and Recover Faster
• ComfyUI Dependency Conflicts
• ComfyUI No Module Named Error: When It Is Safe to Ignore
• ComfyUI No Module Named 'llama_cpp'
• ComfyUI Plugin Management
• Troubleshooting Decision Tree

Need the fastest path?

If your environment is already unstable, download Wonderful Launcher first. If the environment is still blocked after that, use expert help as the second step.

Source References

• ComfyUI troubleshooting overview
• ComfyUI custom node troubleshooting guide
• ComfyUI model troubleshooting guide
• ComfyUI Manager installation guide