# UXP panel always fails with “Cannot resolve module: main.js” — even for minimal plugin

**URL:** https://forums.creativeclouddeveloper.com/t/uxp-panel-always-fails-with-cannot-resolve-module-main-js-even-for-minimal-plugin/11261
**Category:** Photoshop
**Created:** [August 4, 2025, 7:50pm UTC](https://forums.creativeclouddeveloper.com/t/uxp-panel-always-fails-with-cannot-resolve-module-main-js-even-for-minimal-plugin/11261 "2025-08-04T19:50:35Z")
**Posts on this page:** 7
**Page:** 1

<div class="post-metadata">

### Author: ![lior](https://avatars.discourse-cdn.com/v4/letter/l/3ec8ea/32.png) [@lior](https://forums.creativeclouddeveloper.com/u/lior)
#### Post date: [August 4, 2025, 7:50pm UTC](https://forums.creativeclouddeveloper.com/t/uxp-panel-always-fails-with-cannot-resolve-module-main-js-even-for-minimal-plugin/11261/1 "2025-08-04T19:50:35Z")

</div>

Hi everyone,

I’m experiencing a persistent issue when trying to load a basic UXP panel plugin in Photoshop — both in “Add Plugin” mode and in Webpack-based projects.

No matter what I do, the plugin fails to load and gives me this error:

```auto
Uncaught Error: Cannot resolve module: main.js

```

This happens even when I try the simplest possible plugin:

- `manifest.json` (with manifestVersion 5)

- `index.html` with a single `<sp-button>` and inline JS

- No `main.js` defined anywhere in the manifest

Here’s what I’ve already ruled out:

- No `"main"` field in the manifest

- No syntax errors in `index.html`

- Plugin is added via “Add Plugin” from the `dist/` folder

- Tried both minimal plugin (no build) and Webpack-based plugin

- Tried Photoshop 25.x and also reverted back to version 22.2

- Tried with UXP Developer Tool v1.7.0+

- All files (manifest, html, js) are in correct locations

- Tried from local drive (not UNC path)

- Even test plugins with **just a button and text** result in this error

This issue has been consistent across plugin types — even when `index.js` is completely empty or not referenced.

What might be causing UXP to expect a `main.js` file that doesn’t exist?  
Is this fallback behavior? A bug in UXP? Something environmental I’m overlooking?

Any help or ideas would be deeply appreciated!

Thanks 🙏  
— Lior

---

<div class="post-metadata">

### Author: ![AnthonyK](https://avatars.discourse-cdn.com/v4/letter/a/85f322/32.png) [@AnthonyK](https://forums.creativeclouddeveloper.com/u/AnthonyK)
#### Post date: [August 5, 2025, 2:16am UTC](https://forums.creativeclouddeveloper.com/t/uxp-panel-always-fails-with-cannot-resolve-module-main-js-even-for-minimal-plugin/11261/2 "2025-08-05T02:16:57Z")

</div>

I just use vanilla JavaScript for my plugins and have the following line in my index.html file

`<script src="index.js"></script> `

which is the JavaScript file that is the backend for the HTML.

Not sure if that will help or not.

Also, UXP Developer Tool has a File \> Create Plugin option that might also be useful for getting started.

---

<div class="post-metadata">

### Author: ![lior](https://avatars.discourse-cdn.com/v4/letter/l/3ec8ea/32.png) [@lior](https://forums.creativeclouddeveloper.com/u/lior)
#### Post date: [August 5, 2025, 7:24am UTC](https://forums.creativeclouddeveloper.com/t/uxp-panel-always-fails-with-cannot-resolve-module-main-js-even-for-minimal-plugin/11261/3 "2025-08-05T07:24:43Z")

</div>

Thanks!

I tried both simple and Webpack-based plugins — even a super minimal one with just a button and no build or imports. Still getting the same `main.js` error, and the panel stays empty.

At this point I’m thinking —  
**Could this be caused by company-level restrictions or missing admin rights?**

Like maybe:

- UXP WebView is blocked?

- UXP Dev Tool isn’t running with enough permissions?

- Something in Photoshop is sandboxed?

Anyone ran into this kind of thing before?

Appreciate any ideas!  
— Lior

---

<div class="post-metadata">

### Author: ![philipbuckley](https://avatars.discourse-cdn.com/v4/letter/p/db5fbb/32.png) [@philipbuckley](https://forums.creativeclouddeveloper.com/u/philipbuckley)
#### Post date: [August 5, 2025, 10:46am UTC](https://forums.creativeclouddeveloper.com/t/uxp-panel-always-fails-with-cannot-resolve-module-main-js-even-for-minimal-plugin/11261/4 "2025-08-05T10:46:34Z")

</div>

> [@lior](#):
>
> a super minimal one with just a button and no build or imports

If you package that up and post it here, I’d be happy to test it on my machine – to see whether I see the same problem.

Philip

---

<div class="post-metadata">

### Author: ![Karmalakas](https://sea1.discourse-cdn.com/flex015/user_avatar/forums.creativeclouddeveloper.com/karmalakas/32/1048_2.png) [@Karmalakas](https://forums.creativeclouddeveloper.com/u/Karmalakas)
#### Post date: [August 5, 2025, 11:23am UTC](https://forums.creativeclouddeveloper.com/t/uxp-panel-always-fails-with-cannot-resolve-module-main-js-even-for-minimal-plugin/11261/5 "2025-08-05T11:23:43Z")

</div>

What’s your manifest (you may skip the icons)?

---

<div class="post-metadata">

### Author: ![lior](https://avatars.discourse-cdn.com/v4/letter/l/3ec8ea/32.png) [@lior](https://forums.creativeclouddeveloper.com/u/lior)
#### Post date: [August 5, 2025, 12:10pm UTC](https://forums.creativeclouddeveloper.com/t/uxp-panel-always-fails-with-cannot-resolve-module-main-js-even-for-minimal-plugin/11261/6 "2025-08-05T12:10:23Z")

</div>

> **[UXPMinimalPlugin.zip](https://wetransfer.com/downloads/0d0b963d233a603b0f67e55f1548421820250805120420/116aa8?t_exp=1754654660&t_lsid=ba336ac9-dbac-4e5a-90a4-5b3b5086d763&t_network=link&t_s=download_link&t_ts=1754395460)**
>
> 1 file sent via WeTransfer, the simplest way to send your files around the world

Thanks so much for the help!

Here’s a ZIP of the minimal plugin I tested:  
📎 **[UXPMinimalPlugin.zip]**

It includes only:

- a manifest.json

- a basic index.html with a `<button>`

- one line of inline JavaScript that updates a `<pre>` tag when the button is clicked

No imports, no modules, no build tools — just raw HTML + JS.

Even this fails to display anything in the panel on my machine.  
If anyone can try it on their side, I’d really appreciate knowing if it works — or if something in my environment might be blocking it.

Thanks again 🙏  
— Lior

---

<div class="post-metadata">

### Author: ![philipbuckley](https://avatars.discourse-cdn.com/v4/letter/p/db5fbb/32.png) [@philipbuckley](https://forums.creativeclouddeveloper.com/u/philipbuckley)
#### Post date: [August 5, 2025, 2:58pm UTC](https://forums.creativeclouddeveloper.com/t/uxp-panel-always-fails-with-cannot-resolve-module-main-js-even-for-minimal-plugin/11261/7 "2025-08-05T14:58:56Z")

</div>

Someone will no doubt correct me if I am wrong, but I don’t think you can have a plugin without a single javascript file.

If I take out these lines that you have in your manifest:

```auto
      "panel": {
        "mainPath": "index.html"
      }

```

And add this line at the top level:

```auto
  "main": "index.html",

```

Then it does get past the `Uncaught Error: Cannot resolve module: main.js` error, but throws this error:

```auto
Uncaught UxpRuntimeError: Refusing to load inline script tag as executable code. Code generation is disabled in plugins.

```

Which makes me think you can’t do inline scripting as you are trying to.

If I comment out the script tag that you have in your index.html file, then the plugin does load showing the panel and button . . . but, of course, the click of the button isn’t handled.

If I were setting this up, I would change the manifest as above and remove that script tag from the index.html file.

I would then create a javascript file in my folder. It can be named “main.js”, or ‘index.js” as @AnthonyK (above) does, or whatever.

It needs to be linked to from the index.html file, so in the head tag of the index.html file, goes the line @AnthonyK offered:

```auto
<script src="index.js"></script> 

```

In this index.js file (the primary javascript file) there are certain things you need. You need to require entrypoints and you need an entrypoints.setup() function as the first function. I would be inclined to copy the sample code from here:

[https://developer.adobe.com/photoshop/uxp/2022/guides/uxp\_guide/uxp-misc/manifest-v5/#entrypointssetup-using-promises](https://developer.adobe.com/photoshop/uxp/2022/guides/uxp_guide/uxp-misc/manifest-v5/#entrypointssetup-using-promises)

You’ll just need to modify it for your plugin. In particular, (1)

Change the first line from

```auto
import { entrypoints } from "uxp";

```

To:

```auto
const { entrypoints } = require("uxp");

```

(2) where it has

```auto
panels: {
        panelA:

```

You will have the id of your panel:

```auto
panels: {
        minimalTestPanel:

```

(3) You can take out the commands section from that sample code, the reference to panelB and invokeMenu and menuItems (unless you are planning to use the panel flyout menu).

Finally, hooking up the click event listener . . .

I would often add that in the plugin create lifecycle hook. So you could just add the code you currently have in your script tag there. Your entrypoints.setup() function would look like this:

```auto
entrypoints.setup({
    plugin: {
        create() {
            console.log("Plugin has been loaded, plugin.create has been triggered.");

    document.getElementById("btnTest").addEventListener("click", function() {
      document.getElementById("output").textContent = "✅ Plugin works!";
    });

        },

```

That will work, but I would normally separate out the function I am calling on click.

So my entrypoints.setup() function would look like this:

```auto
entrypoints.setup({
    plugin: {
        create() {
            console.log("Plugin has been loaded, plugin.create has been triggered.");

			document.getElementById("btnTest").addEventListener("click", handleClick);
			
        },

```

And at the bottom of my file I would have:

```auto
function handleClick(theEvent) {
	document.getElementById("output").textContent = "✅ Plugin works!";
}

```

Hope all that helps  
Philip