Error: Filename is Invalid

Hi. I'm receiving an error when I try to save the CMS fields of a portfolio item within the Payload admin panel (Below in this thread is a screenshot). The Portfolio collection is the only change I've made to this next-customer-server repo, so I don't know what to debug. I'm a beginner so the answer is most likely obvious.

[10:01:07] ERROR (payload): ValidationError: The following field is invalid: filename
    at new ExtendableError (C:\git\White_Polaroids\WhitePolaroids6\node_modules\payload\src\errors\APIError.ts:26:11)
    at new APIError (C:\git\White_Polaroids\WhitePolaroids6\node_modules\payload\src\errors\APIError.ts:43:5)
    at new ValidationError (C:\git\White_Polaroids\WhitePolaroids6\node_modules\payload\src\errors\ValidationError.ts:8:5)    
    at create (C:\git\White_Polaroids\WhitePolaroids6\node_modules\payload\src\collections\operations\create.ts:214:11)       
    at processTicksAndRejections (node:internal/process/task_queues:95:5)
    at async createHandler (C:\git\White_Polaroids\WhitePolaroids6\node_modules\payload\src\collections\requestHandlers\create.ts:19:17)

"The following field is invalid - filename"

import { CollectionConfig } from 'payload/types';
import slug from '../fields/slug';
import { Type as MediaType } from './Media';

export type Type = {
  title: string
  featuredMedia: MediaType
  previewMedia: {
    media: MediaType
  }[]
  location?: string
  slug: string
  meta: MetaType
}
const Portfolio: CollectionConfig = {
slug: 'portfolio',
admin: {
    useAsTitle: 'title',
},

fields: [
    {
      name: 'title',
      type: 'text',
      required: true,
    },
    {
        name: 'featuredMedia',
        label: 'Featured Media',
        type: 'upload',
        relationTo: 'media',
        required: true,
      },
      {
        name: 'location',
        label: 'Location',
        type: 'text',
        required: false,
        admin: {
          position: 'sidebar',
        }
    },
    {
    name: 'images',
    type: 'upload',
    relationTo: 'media',
    filterOptions: {
        mimeType: { contains: 'image' },
    hasMany: true,
    required: true,
  },
},
],
};

export default Portfolio;

 import { buildConfig } from 'payload/config';
import dotenv from 'dotenv';
import Page from './collections/Page';
import Media from './collections/Media';
import Portfolio from './collections/Portfolio';

dotenv.config();

export default buildConfig({
  serverURL: process.env.PAYLOAD_PUBLIC_SERVER_URL,
  collections: [
    Page,
    Media,
    Portfolio,
  ],
});

Here's a video screenshare:

I've run yarn again - packages are up to date

The EPERM error is a standard occurance when the server is already running. I don't think that is related to this issue.

I've edited the Type to include the location field

export type Type = {
  title: string
  slug: string
  text: string
  location?: string
}

I assume I must run yarn dev again or the changes don't reflect? After I run yarn dev I get this message:

 PS C:\git\White_Polaroids\WhitePolaroids6> yarn dev
yarn run v1.22.19
$ ts-node server.ts
[11:09:57] INFO (payload): Connected to Mongo server successfully!
[11:09:57] INFO (payload): Starting Payload...
info  - Loaded env from C:\git\White_Polaroids\WhitePolaroids6\.env
webpack built 0cea50bd02cd37f88e22 in 14623ms
webpack compiled successfully
<w> [webpack.cache.PackFileCacheStrategy] Caching failed for pack: Error: No serializer registered for ConcatSource
<w> while serializing webpack/lib/util/registerExternalSerializer.webpack-sources/ConcatSource -> Array { 2 items } -> ConcatSource

It doesn't provide the success message I received the first time I started the server. The error persists, though I wonder if that's because the server isn't refreshing or if the Type change has had no effect?

Repo: