Apple has released iOS 8.1.2 this afternoon with a handful of bug fixes and other improvements. Specifically, the release notes say the update addresses an issue where ringtones purchased through the iTunes Store may have disappeared from users' devices.
You can access the new firmware over the air via Settings > General > Software Update, or via iTunes by connecting your iPhone, iPad or iPod touch to a computer. But as usual, we recommend that users who are jailbroken, or plan to jailbreak, avoid the update for now.