He clicked the "Update" button in his Creative Cloud app. A progress bar appeared, spun for thirty seconds, and then delivered the killing blow:

Pro tip: Look for the official Adobe helpx article titled "Camera Raw 12.2.1 installation instructions." The download links inside are authentic.

Forget 12.2.1. Use Adobe DNG Converter to convert new raw files to DNG, then open them in CS6’s built-in ACR 9.x.

Always verify your software compatibility before downloading. If unsure, use the free Adobe DNG Converter as a universal bridge between new cameras and older raw processors.