If I use the define pages editor and I install a new release, will the changes I make in there be lost? I created my own template and I'm using it. Will the changes go in my custom template directory? Also getting a protection error "Error: I can not write to this file. Please set the right user permissions on: /includes/languages/english/html_includes/define_main_page.php"

That's not where my language file is. Its "/includes/languages/my_template/..." I created it when I created my template as the FAQ's instructed.