BuddyPress.org

First of all, it’s not a database version. CSS in WordPress and BuddyPress has those “get” parameters in the URL as a means of forcing browsers to refetch the file rather than use its cached version. For example, when BuddyPress is upgraded in v1.3, you don’t want people to be loading the browser cache version of the CSS for v1.2. This is exactly what hnla told you above four weeks ago.

Secondly, if your theme is trying to load two versions of that file, it’s because in your child theme (or customised version thereof) is calling it twice. I can’t comment where or how this could be happening as we can’t see any custom script you’ve put into your theme.

Finally, you should be safe to copy and paste the php snippet r-a-y gave you two weeks ago into your functions.php; just be sure to paste it before the “?>” line at the bottom of the file.