Adobe has discovered the compatibility issues listed below with running Photoshop with macOS 10.12 (Sierra).
Adobe strongly recommends that customers update Photoshop 2017 prior to updating to macOS 10.12 (Sierra).
Older versions of Photoshop were not designed, nor extensively tested to run on macOS Sierra. We strongly recommend that customers do their own testing on a non-production partition to ensure that new operating systems work with their current hardware and drivers (printing, etc). You may wish to remain on an older version of the OS that is compatible with prior versions of our software.
If you do encounter issues not already documented, feel free to report them on our feedback site.
Photoshop CC 2015.5.1 or earlier
macOS 10.12 Sierra
Adobe has discovered the compatibility issues listed below when running Photoshop CC 2015.5 and earlier on macOS 10.12 (Sierra).
Photoshop would crash while printing on macOS Sierra 10.12.
For some printers, ensuring your printer driver is up-to-date will fix stability issues. Note: Just updating the driver may not work. You need to delete the driver, delete the printer, install the latest driver then install the printer. See this document from Apple on troubleshooting printing on OS X: Resolve Printer issues on your Mac.
Solution: Change the keyboard shortcut for Siri.
Solution: Update to Photoshop CC 2017
Workaround: For prior version of Photoshop, hover over the scrollable area and use the mousewheel or trackpad gesture to scroll the panel instead of clicking on the scroll bar and dragging it up and down.
Workaround: Save your images and/or HTML from Save for Web and open them from the Finder in the browser of your choice.
Our engineers are working on a complete solution for a future update of Photoshop CC.
Workaround: Select Preferences > General. Deselect Show Messages.