Apple has released Mac OS X 10.10.4, which includes improvements for Photos and Mail. It also fixes several bugs (including the “discoveryd” service).
According to Apple, the update:
° Improves networking reliability;
° Improves Migration Assistant reliability;
° Addresses an issue that prevented certain monitors from functioning properly;
° Improves the reliability of upgrading iPhoto and Aperture libraries to Photos;
° Improves reliability when syncing photos and videos to the iCloud Photo Library;
° Addresses and issue that causes Photos to quit unexpectedly after importing some Leica DNG files;
° Resolves an issue that could delay outgoing email messages in Mail;
You can obtain OS X 10.10.4 at the Mac App Store.