– Photos may show black or missing thumbnails when using Time Machine to restore a Photos library that was upgraded from Aperture
Known issues with using iOS 8.1.3 or earlier with Photos for OS X and iCloud Photo Library betas:
– Manually edited dates of photos and videos may revert to their original dates taken.
– Photos may crash when folders containing albums are removed from Recently Deleted. Delete albums individually to avoid crashes.
Important: We recommend using the current release of iOS 8.2 or later with the Photos for OS X and iCloud Photo Library betas. Always back up your photo library by doing regular Time Machine backups of your Mac.
Important Information About Photos for OS X and iCloud Photo Library
Please back up your Mac and read the following information before installing the OS X Yosemite 10.10.3 update and upgrading your photo library.