: Direct installers for legacy versions like CC 2015.5.1 were historically provided by Adobe for troubleshooting.
For users looking to install this specific version, note that Adobe typically recommends using the to manage updates.
: To install older versions, you can open the Creative Cloud app, find Photoshop, and select "Other Versions" to see if it remains available for your subscription. Adobe #Photoshop CC 2015 - Top 5 Features
: Improvements to the Artboards feature, including the ability to duplicate layers or layer groups into other artboards and quickly change artboard backgrounds. Improvements in v17.0.1 (Update 1)
: Resolved crashing issues and problems where subtools would revert to primary tools after using keyboard shortcuts.