SharePoint Framework v1.21.1 release notes

This is a minor bump that fixes the issues around SharePoint Framework solution packaging, provides a fix on a regression related on the CSS handling with the previous released 1.21 version.

Tip

It's safe to keep on using SharePoint Framework 1.21 version (if you don't have CSS issues with it), but we do recommend using always the latest version in the production, which in this case would be the 1.21.1, which has fixes on the reported GitHub issues as listed below.

Released: May 3, 2025

Important

This page addresses details related to a specific SPFx release version. This page doesn't include additional SPFx prerequisites that must be installed in order to develop SPFx solutions, including Node.js, Yeoman, and other tools.

To learn more about these prerequisites, see Set up your SharePoint Framework development environment.

Install the latest version

Install the latest release of the SharePoint Framework (SPFx) by including the @latest tag:

npm install @microsoft/generator-sharepoint@next --global

Upgrading projects from v1.21 to v1.21.1

In the project's package.json file, identify all SPFx v1.21 packages. For each SPFx package:

1. Uninstall the existing v1.21 package:

   npm uninstall @microsoft/{spfx-package-name}@1.21
   

2. Install the new v1.21.1 package:

   npm install @microsoft/{spfx-package-name}@latest --save --save-exact
   

Warning

Upgrading from a previous minor version requires changes across package versions, build configuration files, and toolchain settings that vary depending on your source version. Manually updating package.json alone will result in build failures.

Tip

To upgrade this project, run:

npx -p @pnp/cli-microsoft365 m365 spfx project upgrade --toVersion 1.21.1 --output md

This analyzes your project and outputs all required changes, including a single script to apply them in one go.

Note

The CLI for Microsoft 365 is an open-source solution with active community providing support for it. There is no SLA for the open-source tool support from Microsoft.

Fixed Issues

Here's a list of specific issues fixed around SharePoint Framework since the previous public release.

• #10205 - SPFx 1.21 - SCSS/CSS Module hashes being applied twice, styling not working
• #10207 - SPFx - Styles not being applied in newest version of SPFx 1.21

Also following issue has been fixed and the server side update is currently rolling in production. This means that the fix will be applied on server side without changes on the client side packages.

• #10053 - Web Part Missing in Toolbox After Running Gulp Serve