If you're like me and just upgraded to the Canon 5D Mark III system (congrats!), chances are you're going through the usual headache of upgrading all your software to make it compatible with the new camera files.
Part of the update that is required, if you intend to open files in Photoshop CS6, is to update the Camera Raw plugin to version 7.1 or newer.
I downloaded what I thought was the proper update from Adobe's website and repeatedly got error code U44M2P15 and couldn't understand why. (My initial thought was maybe I would have to upgrade to Photoshop CC...but thankfully this was not the case).
Buried deep in an Adobe forum I found a support ticket where a technician said restarting your computer should take care of the error, and if you use the direct download version of the update you should have no problems with it.
You can download the Camera Raw 7.1 Update below (for MAC). Be sure to restart your computer before attempting to install. Note: you should be updating from Camera Raw ver. 7.0. If you are using an earlier version, you may have to update to 7.0 first in order to successfully update.