# My ComfyUI workflow is failing. How do I fix it?

First off, just being real, loading giant workflows with tons of custom nodes and unknown models can be tricky. If you’re just getting started, try one of the [pre-loaded workflows](https://learn.thinkdiffusion.com/) from our collection first. It’s way faster and helps you confirm everything’s working.

Still want to load your own? No problem. Here’s how to do it right.

\
**Download the workflow file and drag & drop it into your ComfyUI window.**

<figure><img src="https://651881471-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FPs0Rc5V1zpir2xwXrPrZ%2Fuploads%2FPs5oSyntWLix03Ts7t47%2FScreen%20Recording%202025-05-14%20at%208.43.40%E2%80%AFPM.gif?alt=media&#x26;token=dabc069c-85a4-4ec0-a601-fc892d05f3ce" alt=""><figcaption><p><strong>Download the workflow file and drag &#x26; drop it into your ComfyUI window.</strong></p></figcaption></figure>

<br>

### 1. Check your machine and app version

Some workflows require more memory or a specific version of ComfyUI/other apps to run correctly. If the workflow silently fails, this could be a potential reason.<br>

* If you're using a workflow from GitHub or CivitAI, check if it mentions:
  * Required ComfyUI or app version
  * Specific machine sizes needed for the workflow
* Map the app versions you need with the app versions on ThinkDiffusion:

<figure><img src="https://651881471-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FPs0Rc5V1zpir2xwXrPrZ%2Fuploads%2FtNfpkO3HyZu6UytbVKdm%2Fimage.png?alt=media&#x26;token=148bc3aa-2ba1-422c-81f4-c6c4212d4c36" alt=""><figcaption><p>Map the app versions you need with the versions on ThinkDiffusion:</p></figcaption></figure>

* Ensure that you're using the correct machine size you need:

<figure><img src="https://651881471-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FPs0Rc5V1zpir2xwXrPrZ%2Fuploads%2Fq6bfRSY6qt2mQNgAXfSL%2Fimage.png?alt=media&#x26;token=ae6ee7ae-5822-42ce-b744-d161fb6032d6" alt=""><figcaption><p>Ensure that you're using the correct machine size you need</p></figcaption></figure>

***

### 2. Install Missing Custom Nodes

Workflows built with custom nodes need those nodes installed. If the workflow refers to a node that doesn’t exist, ComfyUI will quietly break or fail to load.

*If you see red nodes in your workflow, you need to install missing custom nodes:*

1. Go to ComfyUI Manager
2. Click "Install Missing Custom Nodes"
3. Select and install all missing nodes from the list

<figure><img src="https://651881471-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FPs0Rc5V1zpir2xwXrPrZ%2Fuploads%2FGEIkpi9WdmLGrk7miUMG%2Fimage.png?alt=media&#x26;token=e6fa3582-7fc3-4eac-b2be-73e22d4a9849" alt=""><figcaption><p><em>If you see red nodes in your workflow, you need to install missing custom nodes</em></p></figcaption></figure>

<figure><img src="https://651881471-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FPs0Rc5V1zpir2xwXrPrZ%2Fuploads%2F7NIa1XYltaPwy9Plf70i%2Fimage.png?alt=media&#x26;token=d7a12492-98a9-4b94-bd8c-612eb35767e6" alt=""><figcaption></figcaption></figure>

***

### 3. Install Missing Models&#x20;

***

### 4. Bad custom nodes

Bad custom nodes and too many nodes cause launch issues. For Comfy, bad extensions usually don’t crash the app - they just don’t get loaded. But in A1111, a bad extension can break launch entirely. You have to delete or remove it.

***

### Check the logs | How To Access Logs In ThinkDiffusion

&#x20;*If your workflow is taking a while, and you’re not sure if it’s still running or stuck, check the **Logs*** ***file**. They’re especially helpful for complex workflows.*

**How to access app logs in ThinkDiffusion?**

{% hint style="info" %}
💡Under each app folder is a `logs` folder. Inside that folder, you’ll find a log file that matches the machine ID in your URL. So for comfyui it will be under the `/comfyui/logs/` folder.
{% endhint %}

<figure><img src="https://651881471-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FPs0Rc5V1zpir2xwXrPrZ%2Fuploads%2FR5MlNjDiziN48ZpjisTt%2FScreen%20Recording%202025-05-14%20at%208.53.33%E2%80%AFPM.gif?alt=media&#x26;token=d905da89-0f3f-4401-bce2-6c74f5051035" alt=""><figcaption></figcaption></figure>

If you're still confused, feel free to reach out to our support team on the ThinkDiffusion[ Discord here](https://discord.com/invite/hAm87ApunD). Don't forget to attach the `logs file` as it helps them resolve your query much faster.&#x20;

\
**Other resources:**

*