Every experience in Office is designed using the principle “the user is in control.” It’s critical that customers are the ones who make choices about their user experience, ensuring it fits their specific needs and workflows.

Customers have asked for greater user control over add-in launch behavior in Office. Specifically, integrations into our applications via our add-in framework have been automatically appearing when documents are opened without user notice and without the ability to disable that behavior, causing confusion and frustration.

After careful consideration, we are making three adjustments to the behavior of add-ins distributed through the Microsoft Marketplace to address this customer feedback:

• First, starting on March 2nd, to ensure user control, add-ins will no longer be able to configure themselves to automatically display a task pane on document launch (also known as auto-open). Add-ins will not be able to (1) programmatically set the AutoShowTaskpaneWithDocument property via office.js nor (2) programmatically load a task pane using the showAsTaskpane API unless that call results from an explicit user action (e.g., from the user clicking on a button on the Ribbon). In a forthcoming update, we will enable add-ins to explicitly request user consent to be automatically loaded via an API.
• Second, in a forthcoming update, if a user closes an automatically launched task pane, it will no longer automatically load when the document is subsequently opened, as Office will remove the AutoShowTaskpaneWithDocument property whenever the user takes action to close the add-in.
• Third, in a forthcoming update, users will no longer be automatically prompted to install add-ins when opening a document unless that add-in is required for the document to function or display correctly. Specifically, a prompt appears in the following cases:

–  Excel: When the workbook uses custom functions provided by an add-in and cannot calculate correctly without it.

–  Excel and PowerPoint: When the file contains content add-ins that must be loaded for a worksheet or slide to render correctly.

With these changes, developers should consider updating their product documentation and add-in experiences to guide their users on best practices for inviting others to benefit from their add-in. For example, users could add a note about the add-in when sharing a document with others or embed a link to the Microsoft Marketplace listing in an appropriate place in the document.

These changes do not affect the runtime behavior of add-ins—they will only impact the conditions under which the add-in can automatically launch UI without explicit user choice.

See also

Show or hide the task pane of your Office Add-in

Automatically open a task pane with a document