What type and version operating system are you using, Mac or Windows and the exact version.
What version of Photoshop are you using and what version of ACR.
When was the last time you restarted your computer?
can you reboot and try the update again?
something must have gotten gubbered up........
Mac OS version 10.11.1
20160113.r.355x64 (I don't know where to look for what version of photoshop I'm using... I'm hoping these numbers tell you?)
Camera Raw Plugin version 126.96.36.1998
And I've restarted my computer a few times trying to right this...
The Camera Raw you have installed isn't up to date. The most current version is Camera Raw 10.1.1.
Camera raw support to camera raw 9.10.1