Wordpress Child Theme Not Appearing In Dashboard
Template: parameter is wrong:
Template. (required) directory name of parent theme, case-sensitive.
http://codex.wordpress.org/Child_Themes
It should read Template: PlatformPro_v1.3.0
A child theme is part of your activated theme. So if you activate Platformpro, and you have the child theme folder in the parent theme folder, it will be activated once you activists the parent theme.
As long as your path name is correct, what you have showed above is exactly what you should be doing.