I switched to different theme from theme *26 - Productivity Applications* to to *101- Cloud Apps*.
After that I noticed that all of my Page Items UI template has been changed to No Label from Optional.
Any clue? How will I mass update back to Optional?
For the application in question, navigate to Shared Components > Templates, and select the Replace Templates link from the Tasks region to the right of the page, 4000:4003. On the first page of the wizard, set Template Type to "Label", and click Next. On the next step, set the following:
Change From = No Label
Change To = Optional
Complete the wizard, and you'll have carried out a bulk update of the labels in your application.