With the October 14 update of Windows 11, Studio Pro 9, 10, and 11 can become unusable. Studio Pro shows errors in different panels (for example design properties and toolbox) and editors (for example page, microflow, nanoflow, and rule editor).
If you see the message Hmmm... can't reach this page with an error code of ERR_CONNECTION_RESET, in a tool panel or editor, your workstation is probably affected.
The fix for this is to install "Security Intelligence Update for Microsoft Defender Antivirus - KB2267602 (Version 1.439.210.0)".
See the status page for more information.

Extensibility: Web API Release Notes

Last modified: August 22, 2025

These release notes cover changes to the Extensibility API for Web Developers.

Version 11.2.0

We included a new method for initializing the studio Pro API. (this is a breaking change) For more information, see Getting Started with the Web Extensibility API.
We introduced a new command registration API. For more information, see Commands API.

Version 11.1.0

We introduced a new Editors API under studioPro.ui.editors, which allows you to get the active document and open the default editor for a document. For more information, see Editor API.

Version 11.0.0

We introduced a new API for showing modal dialogs from web extensions. It is available under studioPro.ui.dialogs in the web extensibility API. For more details and practical examples, see Open a Modal Dialog.
We introduced a new API for accessing user preferences from web extensions, which retrieves the user’s selected theme preference (light or dark) and language settings (for exampl, en-US). It is available under studioPro.ui.preferences in the web extensibility API. For more details and practical examples, see Show User's Preferences.
We introduced a new API for showing notification popups from web extensions. It is available under studioPro.ui.notifications in the web extensibility API. For more details and practical examples, see Show a Pop-up Notification.

Version 10.24.0

No user facing changes. However, the extension package version must be the same as your Studio Pro version.

Version 10.23.0

No user facing changes. However, the extension package version must be the same as your Studio Pro version.

Version 10.22.0

No user facing changes. However, the extension package version must be the same as your Studio Pro version.

Version 10.21.0

The first beta release of the Web Extensibility API.