Starting July 22, 2014, CloudKit will require iOS 8 beta 4 or OS X Yosemite Developer Preview 4. To ensure uninterrupted development of your CloudKit enabled apps, download and upgrade to these versions today.
We will perform a server-side data wipe on all CloudKit public databases on July 22. If you are using iCloud containers with public databases, consider creating a copy of your data so that you can re-upload once the data wipe is complete. iCloud Drive, iCloud Photo Library, and Mail Drop will not be impacted by the targeted data wipe.