Sounds like an incomplete installation of the Camera Raw plug-in. Normally when ACR is installed (e.g., 8.2, 8.3, etc.) the color profiles should get installed as well. Apparently, that doesn't actually happen in some cases. Ugh.
The workaround, as you discovered, is to use the DNG Converter installer (which also installs the same set of profiles). That will guarantee the profiles will be available (for both DNG Converter and the Camera Raw plug-in).