Skip to main content

v4.1.8+ to v4.1.10 migration guide

The Strapi v4.1.8+ to v4.1.10 migration guide upgrades versions of v4.1.8 and above to v4.1.10. This migration guide is needed only for users who experienced missing MIME types on their media when uploading media through the Content API (see GitHub issue #12761). The migration to 4.1.10 consists of 3 steps:

  • Upgrading the application dependencies
  • Installing database migration script (optional)
  • Reinitializing the application

Plugins extension that create custom code or modify existing code, will need to be updated and compared to the changes in the repository. Not updating the plugin extensions could break the application.

Upgrading the application dependencies to 4.1.10

☑️ Prerequisites

Stop the server before starting the upgrade.

  1. Upgrade all of the Strapi packages in the package.json to 4.1.10:
path: ./package.json

// ...
"dependencies": {
"@strapi/strapi": "4.1.10",
"@strapi/plugin-users-permissions": "4.1.10",
"@strapi/plugin-i18n": "4.1.10",
// ...

  1. Save the edited package.json file.

  2. Install the upgraded version:

    💡 Tip

    If the operation doesn't work, try removing your yarn.lock or package-lock.json. If that doesn't help, remove the node_modules folder as well and try again.

Installing database migration script (optional)

This step is only required if some files in your database have their MIME type set to null (see GitHub issue #12761).

To make sure Strapi can load the Media Library, the following migration script file must be added to ./database/migrations. The script automatically sets MIME types for files that miss one, based on their filename. The script will be automatically executed only once at the next launch of Strapi.

To add the script:

  1. In the ./database/migrations folder, create a file named 2022.05.10T00.00.00.fill-files-mime-type.js.
  2. Copy and paste the following code into the previously created file:
path: ./database/migrations
'use strict'

const mimeTypes = require('mime-types');

const BATCH_SIZE = 1000;
const FILE_TABLE = 'files';

async function up(trx) {
let lastId = 0;
while (true) {
const files = await trx
.select(['id', 'name'])
.where('mime', null)
.andWhere('id', '>', lastId)
.orderBy('id', 'asc')

const mimesMap = {};
for (let file of files) {
const mime = mimeTypes.lookup( || 'application/octet-stream';
mimesMap[mime] = mimesMap[mime] || [];

for (let mime of Object.keys(mimesMap)) {
await trx.update({ mime }).from(FILE_TABLE).whereIn('id', mimesMap[mime]);

if (files.length < BATCH_SIZE) {

lastId = files[files.length - 1].id;

async function down() {}

module.exports = { up, down };

Rebuild the application

Run the following command in your project root directory to rebuild Strapi's admin panel:

yarn build

Restart the application

Run the following command in your project root directory to restart the application:

yarn develop