A user can only customize his/her dashboard if user theme editing is enabled. Note that this kind of editing is disabled by default. However, If the user previously customized their home page, the user page is available after upgrade.
To enable user theme editing:
- Click Management.
- Navigate to Extensions > Core Functionality.
- Scroll or filter to the "Users" plugin, then click on it for more details.
- Select the Allow user-customization of the site home page check box.
- Click Save at the top to save your changes.
Now when users log in (or refresh their browser), they will have the Manage User Theme option from their site home page.