Service Pack 1 for Autodesk Revit 2016.

Download:
http://download.autodesk.com/SWDLDDLM/Updates/Revit/2016/SP1/Autodesk_Revit_2016-x64_SP1.exe

Release notes:
http://revit.downloads.autodesk.com/download/2016RVT_SP1/Docs/RelNotes/AutodeskRevit2016-SP1ReleaseNotes.html

Readme:
http://download.autodesk.com/SWDLDDLM/Updates/Revit/2016/SP1/Autodesk_Revit_2016_SP1_Readme.htm