After updating to JetPack ver. 2.2.5, I found 404 responses occurring when notes-widget.min.js sends a GET request to https://widgets.wp.com/languages/ko_KR.json. This occurs only on the admin page, and is detectable via console.
I doubt that it's a browser specific issue, but I'll post my browsing environment anyway. I use chrome 26.0.1410.63 on Ubuntu.
Anyone have any ideas about why this is happening?