I have a Server 2012 R2 machine that consistently fails to install KB2919355, also called Windows Server 2012 R2 Update. I've tried via Microsoft Update and manually. The update shows up in Microsoft Update. It downloads and appears to install. Then on the reboot it says it failed to install the update, rolls back, and reboots. I tried applying the patch manually, following the instructions regarding installation order here:
KB2919442 is installed.
Dism /Online /Cleanup-Image /RestoreHealth
And the fixit here:
Net stop wuauserv
rd /s %windir%\softwaredistribut
Net start wuauserv
I've linked below to an excerpt of the machine's WindowsUpdate.log file, which includes the last attempt to download and install updates.
Installed server roles include IIS, File Services, and WSUS.