Apple’s next version of macOS, called Sierra, is going to be released sometime this fall. Apple has already released early versions of Sierra to beta testers for evaluation over the next couple of months. All Fat Cat Software products will be made compatible with Sierra upon its final release, but in the meantime we do not officially support the Sierra betas, and you may encounter incompatibilities if you try using our software on the beta releases. If you want to ensure you can get actual work done, please continue using El Capitan. Below is the current list of known incompatibilities:PowerPhotos: PowerPhotos will not be able to display or work with photo libraries that have been upgraded using the version of Photos that comes with macOS Sierra. If you wish to browse or copy photos between libraries, you should do so using El Capitan instead. If you have already upgraded a library using Sierra, that library will no longer be readable by El Capitan, so you will also need to revert that library to a backup copy made before upgrading. iPhoto Library Manager, PowerTunes, FlickrExport, and PlistEdit Pro: There are currently no known incompatibilities with Sierra If you do come across issues while running the Sierra beta, do feel free to email us at firstname.lastname@example.org with a bug report. We may not have an immediate solution for you, but we will fix whatever bugs come up before the final release of Sierra. Again, if you do come across a bug and need to get real work done, you should do so using El Capitan instead.