Bug: Polymorphic uploads crash when used in a block within Lexical

[immotus]

Describe the Bug

Polymorphic uploads within a block used in a Lexical editor cause the editor to crash.

For instance, a simple block like this:

export const TestBlock: Block = {
	slug: "test-block",
	fields: [
    {
      type: "text",
      name: "title",
    },
    {
      type: "upload",
      name: "image",
      relationTo: [ "assets", "media" ],
      required: true,
    }
  ],
};

Embedded within a Lexical editor like this:

  fields: [
    {
      name: "content",
      type: "richText",
      editor: lexicalEditor({
        features: ({ defaultFeatures }) => [
          ...defaultFeatures,
          BlocksFeature({
            blocks: [
              TestBlock,
            ],
          })
        ],
      }),
    },
  ],

Initially, it worked as expected, allowing me to create a new document with these blocks and select images. However, attempting to change the upload within the block after saving the document crashes the entire editor to an unrecoverable state.

Video_2025-11-09_024253.mp4

Link to the code that reproduces this issue

https://github.com/immotus/bug-polymorphic-uploads/

Reproduction Steps

1. Clone the repo
2. pnpm i
3. pnpm dev
4. Go to localhost:3000
5. Seed the test database
6. Upload some images into the Assets collection
7. Go to the Test collection and create a new document
8. Add a couple of TestBlocks linking to images in Assets and Media collections
9. Save the document
10. Go to the Test collection and open the newly created document again
11. Try to change images within the blocks to another image from a different collection

Which area(s) are affected? (Select all that apply)

plugin: richtext-lexical, area: core

Environment Info

Binaries:
  Node: 24.8.0
  npm: N/A
  Yarn: N/A
  pnpm: 10.17.0
Relevant Packages:
  payload: 3.63.0
  next: 15.4.7
  @payloadcms/db-mongodb: 3.63.0
  @payloadcms/graphql: 3.63.0
  @payloadcms/live-preview: 3.63.0
  @payloadcms/live-preview-react: 3.63.0
  @payloadcms/next/utilities: 3.63.0
  @payloadcms/plugin-form-builder: 3.63.0
  @payloadcms/plugin-nested-docs: 3.63.0
  @payloadcms/plugin-redirects: 3.63.0
  @payloadcms/plugin-search: 3.63.0
  @payloadcms/plugin-seo: 3.63.0
  @payloadcms/richtext-lexical: 3.63.0
  @payloadcms/translations: 3.63.0
  @payloadcms/ui/shared: 3.63.0
  react: 19.1.0
  react-dom: 19.1.0
Operating System:
  Platform: win32
  Arch: x64
  Version: Windows 11 Pro
  Available memory (MB): 32631
  Available CPU cores: 16

[immotus]

Paul (@paulpopus) and Alessio (@AlessioGr), I suspect it might be related to either a slightly unpolished recently released new feature of Polymorphic Uplods (v3.63.0) or how Lexical handles that feature.

[immotus]

Related to #14363

[paulpopus]

Hi @immotus I can't reproduce this issue following your config and steps

I'm able to edit, add or remove images without errors, as well as change between collection types of the media used. I've also tested this with hasMany and it works as expected for me

Do you think you could reproduce this inside our _community test suite?

[immotus]

@paulpopus I can give it a go if you tell me what the community test suite is.

Also, have you tried returning to the collection, refreshing the page, and attempting to edit the document again? I’ve noticed that it works fine on a newly created document, but crashes if you leave the page and come back. The Lexical editor also seems to behave quite inconsistently – in my other bug report #14359, you can see in the video that it sort of works for a while, you fiddle around with editing, and then it crashes. Everything usually works perfectly when it’s directly embedded into the Payload config, but once in a block, it can be annoyingly and unpredictably buggy. I suspect it’s more to do with Lexical or Blocks rather than the feature itself.

[immotus]

@paulpopus does this error say you anything:

[paulpopus]

@immotus The community test suite is here https://github.com/payloadcms/payload/tree/main/test/_community, alternatively you can use the blank template to provide a completely fresh reproduction, just something to try to isolate the bug more

That error suggests that it was not expecting an object which we use for poly, so the value stored is correct but it's trying to render it directly for some reason. Is your media being deleted?

[immotus]

@paulpopus The media definitely isn't deleted. There are no adapters or anything, so everything is stored locally. In fact, you can see in the video that it occasionally reappears in the drawer and then crashes. So, the media files are definitely there.

I'll start with a blank template first and try to recreate the error. I'll post a link to another repo here if I manage to reproduce it again.

[immotus]

@paulpopus, Okay. Here you go...

The new repository is located at https://github.com/immotus/polymorphic-uploads-blank, based on the blank template, and features a bare-bones configuration.

The bug is still present, but holy moly, it is inconsistent. See the video:

Video_2025-11-11_233353.mp4

It sometimes works, sometimes doesn't. More often, it doesn't, and in a real setup, it crashes at the most inappropriate times, blocking the whole UI. To reproduce, you really need to fiddle with it a little bit - create a document, go back to the collection, edit it again, if it doesn't crash, create another one. Try multiple block, change image in one, then in another, etc.

[immotus]

I'm not a React expert, but it really feels like there is dodgy state management going on with the Lexical component...