Could this be the same as "clear cache" and if there isn't any cache being used you can't clear it? "Data used" would mean the space the program itself occupied. But I could be mistaken.
At the bottom on right side of uninstall, clear data is disabled for all installed apps. I am using those apps it means they must have some occupied space for customised settings, search history, etc..
Could this be the same as "clear cache" and if there isn't any cache being used you can't clear it? "Data used" would mean the space the program itself occupied. But I could be mistaken.