Add New Task Update Actions to Salesforce1

Your organization receives notifications about the “Add New Task Update Actions to Salesforce1” critical update only if the default task layout in your organization has been modified. When you activate this critical update, four new update actions are added to all task page layouts, including custom layouts, and are available in all versions of Salesforce1. The update actions are: Edit Comment (edit the task description), Change Date (change the due date), Change Status, and Change Priority.

User Permissions Needed
To view critical updates: “View Setup and Configuration”
To activate critical updates: “Modify All Data”

AND

“Customize Application”

You can activate this critical update from Setup, by clicking Critical Updates and then clicking Activate for “Add New Task Update Actions to Salesforce1.”

For more information, see It’s Easier to Update Tasks in a List.