The September update to KDE Software Compilation has been released a few hours ago. This version fixes over 50 bugs and brings improvements to the Kontact personal information manager, the Okular universal document viewer, Umbrello UML modeller, Parley vocabulary app and Dolphin file manager.
Plasma Workspaces has been updated to 4.11.12 as well. For the complete official announcement and instructions on how to compile this point release, go here.
A complete list of fixed bugs can be found here.